Amt. of conditioning needed
Stretching & warming pasta machine hand
....some ways to warm clay
....beating clay
Additives (to soften)
Leaching (to stiffen)
Cooling clay (hot hands, weather)
Choppers, food processors, meat grinders
Old or hard clay
Air Bubbles
(click link for a separate page showing tests & info re strength & flexibility
...after using diff. amts of conditioining, diff. brands, etc.
..... )

"CONDITIONING" & Preparing clay for use

Clay (even straight from the package) may be soft, firm, hard, or in-between.

Amount of conditioning needed

The amount of "conditioning" (kneading, rolling, stretching, warming, etc.) that's needed for polymer clay will vary, depending on:
....brand and type of clay (...sometimes even color)
....age of clay
....dryness or aridity of environment conditions
....whether it's been conditioned in the past, and how long ago

It has been thought that the liquid plasticizer in polymer clays would "settle" toward the bottom of the bar over time, and that a lot of remixing was necessary to mix it back throughout the clay to give the baked result strength, flexibility, longevity and a smooth appearance.
.... questions have arisen though as to whether all these factors are true, and whether they're true for all the brands and types of clay
.....some informal tests have been done by clayers (see some results in Tests), and some clayers have asked polymer manufacturers to help clear this up.

From what I can tell at this point, the main things that look convincing are:
"conditioning" is necessary only to make the clay pliable and good to work with (so that it will look and feel smooth when formed, and so the color is even throughout)
.........for some clays, like Fimo Classic, this means a lot of conditioning... for softer clays, much less conditioning
....conditioning does not make a clay stronger (unless any pieces or parts are actually not joined well... which can lead to crumbles & cracks)
....flexibility is affected somewhat, but not in necessarily predictable ways (in fact Premo may actually suffer with "complete" conditioning)
....conditioning (esp. by pasta machine or processor) makes translucent clays less clear (see Translucents > Most Clarity)
--check out the tests for many more variables to consider, and to form your own opinion J

Just to let you know, Polyform has found that polymer clays do NOT need conditioning beyond getting them soft enough to work.
.... Experiments have been done which prove that the strength and durability of the clay is no different when used right from the packet or when conditioned for 15 or 30 minutes. They tested thin strips on up.
.... Also, it is NOT true that the clays which are easier to condition are necessarily weaker. It possibly used to be true, before Premo, which is very easy to condition and tests out stronger than most of the others. That's why I use it. Crafty Owl

Ways to tell if you've conditioned well enough long enough):
...sheets should look supple and a bit shiny ....and handle/drape in a supple manner
...roll clay into a log and bend it over on itself... it should bend fairly easily and should not crack at the top where it's bent
(if you're mixing two colors of clay together... they'll be conditioned when they're fully mixed)

I use the following "fitness test" to determine if the my (leached) clay is right for sculpting :
.....roll the the clay into a ball and cut the ball in half
.....put ball back together by sealing the seams using thumb or finger strokes only
..if the clay loses its shape, it's too soft for modeling
..if the seams blend easily, yet the two hemispheres retain their shape, it's usually just right. K. Dewey

After being conditioned, all clays will firm up a bit over time just from losing the friction and warmth of your hands (often this is desirable because clay can be too mooshy for some things like slicing and detailed shaping)...and it will firm up a even more over a longer time.
...the amount it firms up can be controlled somewhat by protecting it from air, but doing that is not necessary
......of course, whether conditioned or not, clays need to be protected from too much UV light or heat
...clay also needs to be protected from having its plasticizers (oil) leached out (unless that's what you want) can lose some of its plasticizer to a material it's touching (so don't leave your clay on absorbent surfaces for a length of time . . even waxed paper can be absorbent if it's pressed next to clay for some time and there's something on the other side of the waxed paper for the plasticiser to leach into).

Before using any clay that's been conditioned but has sat for awhile since then, you'll just have to check and see how much that particular bit of clay needs to be reworked in order to achieve a pliable state again.

I also think that (some?) clays can be over-conditioned - that's happened to me and the result was that bits came off the surface of the sheets (shredding?).
.......I've done this too... kneaded and rolled the clay to such an extent that bits of clay from the surface pull away. Of course, this was so frustrating, I just kept rolling through (thinking that I could correct it). Dumb! .
....Finally, I let it rest and then it was fine. Donna Kato
(although shredding happened to me with a particular black Fimo clay when trying to mix it with other clays, and letting it rest didn't help).

STRETCHING and WARMING (incl. beating)

Anything that warms and stretches the clay will work to make it pliable and to get rid of any small variations of color in the bar.
(If the clay is hard, like the Fimo Classic brand, you may want to start with a half block or smaller piece.)

don't use anything which will get the clay too hot though (or you'll partially cure the clay)
...see "Warming" below for ways to warm clay

by pasta machine

The easiest and fastest way to make any clay pliable is do it in a pasta machine, if you have one:
...Premo, Kato Polyclay, and of course Sculpey clays, can be put directly into the pasta machine from the package to condition them, as long as they're first cut into slabs just thicker than the pasta machine setting you begin with (geneally, this is the widest setting)... from there the clay can be folded over and passed through time after time unti lit's pliable, or it can be put through thinner settings first and then folded and passed through again and again (...remember not to put any clay into a pasta machine fold side first to avoid incorporating air bubbles in the clay... see much more in Air Bubbles sub-category below)...
...... Instead of folding the clay to get it to blend, cut or tear the clay sheet in half and roll it through. This way it will blend faster too. The less folding you have to do, the better. Less chance to trap air bubbles.. Patty B
...for stiffer or older and stiffer clays, the pasta machine can be used once the clay has gotten at least a little bit warmed (otherwise it will just crumble all over the place)

Because of the mechanics of a pasta machine and the gearing, IMHO it is better to condition at # 3. a wider setting than 3, the teeth on the drive gears (under the "mystery side" of the PM where the thickness control knob is located) are farther apart, and they only engage at their tips.
......they can be easily damaged at a #1 setting, especially if you jam a real thick piece of hard clay through the rollers a thinner setting (#3), the teeth on the drive gears are engaged tighter, therefore you're less likely to damage the gears.
Kathy W.

Here are some tips to conditioning Kato Polyclay in particular (instructions from a Donna workshop I took):
a. Cut your block of clay into medium thick slices.
b. Compress the slices with your acrylic rod (roll over them firmly) on your work surface to soften the clay (this will lessen crumbling when put through the past machine) (... can join flattened slices together side by side)
c. Starting with the #1 setting, run the clay through the pasta machine. Fold and run through again, placing the folded side first through the rollers.
d. Change the setting on the pasta machine to #3, fold the clay and roll through, fold side first..... Fold and roll until conditioned.
(....Kato Polyclay may still have rough edges even when conditioned... the feel of the clay is the indicator for conditioned clay (soft, supple). Margaret D.
...Gail Ritchey's lesson with same instructions
(or use the search at the site using Kato Polyclay Tips)

by hand, etc.
(...this will take awhile if it's hard clay...)

Begin by squishing the clay in your hand.
Roll the clay into a ball.
Then roll it into a longish snake.
Twist it quite a few times.
Bend the snake back on itself, and bend again if it's not too crumbly at this point.
....OR compress the twists into a chunk (accordion style) before or after the bending.
Then roll back into a ball.
......Repeat these steps until the clay doesn't crack at the top of the bend (if it's still cracking, add a few drops of Sculpey Diluent, or some Fimo Mix Quick, translucent, mineral oil, glycerin, Vaseline, or a softer clay, to the clay you're conditioning.)

Linda P. recommends cutting off a thin slab of clay, then rolling it thinner with a brayer, rod or drinking glass(?)... once it's thinned a bit, fold it in half, then roll it thinner again... repeat till sheet looks smooth

lesson on conditioning clay with one's feet ....fold and mash, roll & twist? (clean feet with wipes), at NoraJean's site:

some ways to warm clay

One way to hasten the process of getting any clay ready to use is to warm it. (I may also do this to prepare for a class which will be held in the winter months.) There are various ways to do this, from placing the clay near a light source to placing it on or in something warm.

Another way to warm the clay is to fill a small ziploc bag with uncooked rice and microwave it for about 1-3 minutes. I slip the warmed rice into a terrycloth mitt and it works great. . . or sew into enclosed fabric squares or logs, etc.
.......make a fabric pouch about 8" by 8" and fill it half full with rice... sew up the other end. You can then put this in the microwave for 1 to 1 1/2 min's...
then take a dish towel lay it on top of your rice bag you clay on top of the towel and close it for a few minutes. Leona
...(Dried corn can also be used as a filler, but must be allowed to completely cool before reheating or interior kernals can burn. . . may make moist heat?) pat

"Clay Warmer" by Friendly Clay
For softening Fimo, aside from the food processor/coffee grinder method, the one I favor is the Friendly Clay brand "Clay Warmer." It's sort of like a fold-over flap purse or saddlebag. The 5"x7"cold/hot gel pack that comes with it slips into the "purse," and the flap folds down over it, velcro holding one corner. The idea is to put the purse-with-gel-pack into the microwave and heat on high for 1 to 1 1/2 minutes. Take it out (and I squish the gel around to make sure there are no particular hot spots), open the flap, insert Fimo protected by its plastic wrap or kitchen plastic wrap, close flap, wait 10-20 minutes, then remove. It's *very* warm and pliable.
I've never had mine get too hot for the clay even though I cooked the gel pack too long one time and it burst on one side (that was 1 1/2 minutes in my very efficient microwave--now I use little more than a minute). It works really well for keeping an amount of clay warm while you work too, and you can keep zapping it 30 seconds or so, for however long you need it ( without the clay inside ! ).
I think my warmer cost $10 or $11. They sold the gel packs separately for $5.00 and when I burst the first one, I put it in a Ziploc bag--it still works fine. I bought another gel pack, made my own pouch from cotton fabric and polyester batting, and gave it to my sister. I don't know if they have mail order, but the telephone number on the tag is (408) 379-1696. I think I've also seen them in one of the mail order catalogs. The Friendly Clay people could tell you where to find them too.
I sound like an advertisement for them, but I'm not. I have some physical problems that make it hard for me to use Fimo, so it's been a real help. (It's certainly a lot better than when I used to carry little wads of Fimo around my waist under my shirt all day in a long folded piece of flannel that I tied in back. I used to forget that it was there and found myself at the grocery store, e.g., looking either lumpily pregnant or suspiciously like a shoplifter.) Diane B

For warming the clay, I have found something that works well for me. (I still use the clay warmer for quickly warming, but) I leave a heating pad permanently on my work surface and put one of those metal defroster rectangles (got cheap) on top of it. I keep clay I might work with either on top of it directly, or in a shoebox top on it. It's very nice to be able to have reasonably warm clay at your fingertips (never gets hot, just a little warm). I think the metal radiates the heat all around, more than the heating pad's direct heating of just the bottom of the clay. Works well, anyway, and I'm getting into the habit of turning the heating pad on a little while before working. After that I feel comfortable about leaving it on for chunks of time when I know I'm coming back to the clay. (Oh, I put newspapers under the heating pad, next to the table surface.) Sounds like a lot, but once in place. . . voila! Diane B.

I have a similar gelpack I use to warm clay, and have found that putting it in a cardboard box--preferably a small corrugated one--makes a nice little insulated place while I am working. An insulated lunchbox would probably work, too. Becky Preston

I tried my old warming tray the other day, but it gets a tad too hot. I'm going to try and put a towel or something on it to lessen the heat reaching the clay. I left a thin button on it just to see if it would cure, and it did! So I'll have to fool with it a bit. Miracle
If you can't get success with the towel or such, try buying a rheostat (stained glass makers use them to regulate the heat of the soldering iron (—like a dimmer switch?). It works by passing only part of the current through to the device that is plugged into it, thereby creating a lower temperature than would be possible using the device's temperature controls. Risa

... I put about 1/2 of a small pkg of Fimo in the microwave on the Defrost setting (very low power) for about 30 secs. This warms it up just enough to be slightly pliable. . . . Then I use a straight-sided glass bottle with a tight-fitting cap (from ketchup, soy sauce or the like), filled with hot tap water, as a rolling pin. This will quickly make it ready to go through the pasta machine without requiring too much muscle. Suzanne

I keep a goose-necked lamp hooked up near my working area.... that light bulb can put out some heat! Before I even start, I usually go in and turn it on, then position it down close to the sheet of glass I work on... with my tools lined up on it. It warms everything! Often, I'll pull out whatever colors I plan to work with and put them under there too.... being careful that it's not so close as to actually start the clay baking! When I come in to start working, I reposition the light over my pasta machine... a warmed up pasta machine is a delight!! I eventually move the light back over my work area and work under it... it really keeps the fimo workable...

When I'm about to make a cane I put all the clay I'm going to use on to a cookie sheet and put it into the oven. I set the oven at a very low temperature. By doing this my clay is soft as butter to mix and VERY easy on my pasta machine. My hands never ache from warming up cold stiff clay! #2. . . . it takes about 10 minutes or so for the clay to get warmed up enough for me to want to use it.
I leave all the clay I'm using in the oven, which could be up to 8 hours, until I'm done. My clay is warm all the time! I use a 50/50 mix of Sculpey III and Fimo translucent. Candy

an egg incubator! Wow -- this may be THE new polymer clay must-have-it tool! Old blocks of Fimo softened up enough to be conditioned, and she said she has used it for old canes, too. It's a styrofoam thing -- similar to those cheapie styro coolers, but flatter and wider -- with a window and a dial on the top. It didn't seem to have degree settings, just "warmer" and "warmest", but it maintained a consistent temp of just a little warmer than body temp (she put a thermometer in it). She laid a towel in the bottom and it held a lot of packages of clay.

beating clay

solid clay (bars or wads)

My solution is to bash the clay while still in the wrapper with a rubber mallet on all sides (this compress and compacts it)
... then I remove from wrapper, and condition it further by hand or machine (with a bit of softener if needed, in this case baby oil)
.....this may work especially well for clays that tend to get crumb-y during conditioning, like FimoClassic, but should work for any stiff clay. Garie
Garie's lesson on using a thick wooden rod (plus some Sculpey Diluent-Softener to soften it further)
...putting the clay into a plastic ziptop bag, etc, along with liquid clay or Diluent, then beating with a regular hammer works well too
....... then just slice a hunk of the sheet of pounded clay (which should be just a bit thicker than the thickest opening on the pasta machine) and start rolling through the pasta machine repeatedly (...if it still crumbles too much, repeat with the softener and hammer)
....I use a hammer, with the clay in a plastic bag. My husband thought I was crazy the first time he saw me do that with a new lump of Fimo. Then he tried working with the stuff himself. Lee
...I condition my polymer (particulary Fimo) with a heavy wooden mallet.... hitting it, and and turning over and over. don't have to hit too hard either ...something about it just gets the plasticizer moving...Has worked like a charm for me for a long time. Lori
...hard clay can be beaten into submission with an old rolling pin too ....chop it into1" lumps ... stand up over the clay for the easiest force, and go for it with the rolling pin! Sue
...I pour my clay crumbles (from the food processor?) out onto a sheet of plastic wrap, and fold it back over, then pound with a small (metal?) meat tenderizer mallet (with the little protrusions on it)'s the weight of the pounder, not the force that does it

try driving over it with your car! . . (I'm posting this from my friend - she doesn't want to be identified!)
....first wrap it with plastic or newspaper (in the wrapper or a plastic bag), then just drive over it! ....she swears by this method. Donna

Also, ror old hard canes, take your hand roller (lucite/acrylic rod, or something else) and beat those canes... literally!
... all sides, both ends. The forces applied on the surface cause the molecules to vibrate throughout the cane, which softens the clay....make sure to apply the hits as evenly as possible to minimize distortion when pounding canes. Desiree

(also) I had many old sheets of polymer clay "fabric" that I'd made a year ago which I forgot all about... When I tested them last week they cracked when I touched them. ...So today I 'excited their molecules' by smacking them between their layers of plastic wrap until I'd hit every inch of each. I used both an acrylic rod and then switched to a rubber mallet. I must say IT WORKED like a charm --I later used a lot of them to make mokume gane (slabs) after they were softened up. Carolyn
...I want to further clarify that rubber mallet deal (with sheets of patterned clay).... you'll need to be sure that the clay sheet is covered completely with plastic wrap and that the plastic is smooth or otherwise you're going to be smacking textured lines into the clay which will be hard to even out
....after the sheets have been "worked over" sufficiently, I usually test a corner"'ll then have to run it through the pasta machine several times on the same setting as the sheet was originally run through on. Carolyn

I have a problem with the scrap clay I purchased from Crooked River . . . the black clay that's in all the scrap just refuses to mix with the other clays, and shreds up from the sheet (making a mess in my pasta machine). I've tried adding Diluent while running through the pm but it doesn't help very quickly so a hammer method might work. Diane B.

ADDITIVES (to soften clay)

If the clay is just too firm for your purpose, various things can be mixed into the clay to soften it.

As for softeners, various things will work and not affect the strength of the clay (as long as you don't add huge amts.)... (**however, see Eliz's & Jeanne's warning re mineral oil with TLS below)
. . .Sculpey Diluent, mineral oil, vaseline, Liquid Sculpey, Fimo's Mix Quick, SuperSculpey, glycerin and other soft clays are some of the softeners you can use.

Prewarming the clay and additive a bag by sitting on it, etc., will be a MAJOR help! I also work under a light for extra warmth.. Joanie

SOFT CLAYS: I've heard that if using Mix Quick or a soft clay, no more than 1/4 of the mix should be softener?? That sounds like a lot to me.
--Mix Quick is a long whitish bar of clay and is sometimes available near the Fimo display stand, or by mail order.
--SuperSculpey is usually available (in a & white box) on a shelf under the Sculpey III's ('s fairly translucent and only slightly colored)
......regular translucent clays
..........I add 20% translucent clay t to my Fimo, and it stays soft forever this way and needs very little prep time later
...FimoSoft ... absolutely brilliant for softening up old crumbly Fimo ... it's now soft and icky! Shelley

--Sculpey Diluentis sometimes available on the *top* of the Sculpey display stand or somewhere around it (in a small translucent bottle) or it's available by mail order (NOTE: the bottle is now labeled "Sculpey Clay Softener")
...It's best to add the Diluent after the hard bits are chopped up, a few drops at a time.

--Translucent Liquid Sculpey (a liquid clay) is currently available in small bottles at some craft stores and by mail order.
TLS doesn't seem to impact the color much at all when used to soften other clays -I've even put some in black Fimo and the change was barely noticeable.
....I like the way the clay handles when conditioned this way. I'm a Very thorough mixer. Seems like the clay reconditions faster and wants to stick to itself rather than the tools. . . . I also think that it buffs up easier and nicer.
...Before Premo came out, I used Fimo Classic and would sometimes use the old opaque liquid sculpey to soften it... I found that I really liked the handling of that mix, still firm, but sort of resilient Jody

--vegetable oils seem to work quite well (corn oil, etc.)
I have used vegetable oil many times over a number of years with no problems after baking--only need to be careful on the amount used so you don't get mush. Linda J.

-- glycerin ...Gail Ritchey swears that it is the perfect clay softener! Non toxic, too. Donna Kato
.....glycerin is an alcohol sugar, which is clear, thick and sweet... used in foods and in many other things to make them softer, more lubricated, thicker, etc.'s also soluble in both water and alcohol

--Vaseline works too, but produces a slightly different effect. Desiree (...use just a smear of petroleum jelly or it may be too much)

<Can I blend mineral oil with dry, crumbly clay to make it soft again?>
Yup. (they’re all petroleum products . . .?)
... mineral oil (no more than 10-12 drops per 65 gms or a block of Fimo). A little goes a long way but if you needs tons of mineral oil, you've got a problem that's more serious than just stiff clay.
. . . .start off with a small amount, gradually increase. Remember it is far easier to add oil than remove it, so go very cautiously.
......And for really, really old stiff clay, it can take a few hours for the oil to soak thoroughly soak the clay particles. Be patient.
....Condition the clay with a little oil, stick it in a plastic bag, set it aside under a warm lamp or a warm kitty or something, get back to it after a while, add more oil if necessary...
.....However, I prefer the thicker, laxative-type mineral oil over regular mineral oil (baby oil only?) Desiree
........there (may be) a great difference in the quality or types of mineral oil.
I did some experiments with mineral oil, Sculpey diluent & TLS:
--the items which I used the mineral oil in cracked easier, and had more crackling when mixed with TLS and baked.
--the mineral oil left the TLS milkier or whiter than the Sculpey diluent.|
Again, I have no idea if (Diluent is actually mineral oil) but if so, my mineral oil wasn't the same mineral oil as in the diluent. Jeanne

.......If Diluent has mineral oil in it as a base (and I don't know that it does), I know that it also has other stuff, because plain diluent cures into a rubbery film and mineral oil doesn't. . . . When I've mixed mineral oil into TLS to test it, the cured TLS sheet isn't strong and flexible and clear as TLS or TLS and diluent - it's cloudy and brittle, looks just as if I've under-cured it. Elizabeth
... I think oil makes a fine diluent for stiff clay, but actual Diluent might work better in other applications, such as translucents. I found that oil made the clay sorta grainy, almost "curdled" as I conditioned it, but the finished product was fine. . . . Diluent worked smoother, but on the other hand it has a pretty strong smell and is not so good on your hands. Ginger
...I'm no chemist, but I was reading Nan Roche's explanation for how polymerization occurs and it seemed to me that mineral oil or glycerine or hand lotion or corn oil could create microscopic barriers between the polymer molecules and prevent them from fully fusing. Maybe it wouldn't prevent all or most of them from fusing, but maybe there would be enough molecular surface unfused to create weak spots in the finished pieces. I could be wrong and I'm approaching this issue almost completely from intuition . . . Elizabeth
....It's a lot easier to work the new clay into leftover conditioned clay than it is to start entirely from scratch.
I take about a tablespoonful of clay and add 3 or 4 drops of baby oil (maybe should use the thicker laxative mineral oil instead?). Moosh up that little bit into a sticky mess, then add the same amount of clay. Moosh that up, then add an equal amount of clay- in other words, each time you can take twice as much clay as you did the time before. You can add another drop or 2 of oil as you go along, if necessary. It really goes quite quickly, especially if you're conditioning several blocks. Beth C.

I bought a big bottle of baby oil (it's a slightly lighter petroleum fraction than mineral oil, so it mixes better). author?

Another way to soften hard clay is to leave it touching a softer clay (SuperSculpey, a translucent, or others)
... or leaving it in contact with one of the "softeners" (
MixQuick, glycerin, mineral oil, baby oil, vaseline) for a day or more
--some of the plasticizer will leach into the harder clay
(see more on "marinading"the clay below in
Old-Hard Clay > Marinading)

LEACHING (makes clay firmer)

(see also Sculpting for leaching clays for sculpture work)

If the clay (Sculpey or any other clay --but Fimo Classic?--see below) is just too soft for your purposes (this can also be because it’s very fresh), you can make it firmer by "leaching" it. This removes some of the plasticizer.
(This is important especially when caning because if the clays or the colors you're using are of different firmnesses, some parts will reduce faster than others and cause distortion in the reduced cane --see Reducing > End Caps Method to help if that's the case). . .
...since leaching makes a clay "dryer," it's one way to get a ragged edge on a sheet of clay if you want one for an aged or rock-liek look ("tear"the sheet rather than cutting it)

Do be aware that with leaching, you are taking out both plasticisers and stabilizers. This can leave baked clay somewhat weaker than it would otherwise be. . . . Try to get clay that is close to the consistancy you WANT, and go from there with as little leaching or adding softeners as you can.
. . . Also, raw clay texture changes over time even when wrapped. When I get clay in the big bricks and its too fresh from the factory its soft--just letting it age for a month or three in the package really helps, and doesn't take out the plasticisers and stabilizers. Sarajane Helm
...It depends on the brand. . . .
The chemist as Polyform has told me that stabilizers used in Polyform clays (Premo and Sculpey) are gels and do not leach out. Leaching only removes the plasticiser. Katherine Dewey
...Classic Fimo reacts differently to leaching, in my experience, than the other clays. It ... crumbles. With really fresh fimo I am not sure there is a really simple way to alter it's consistency other than put it on the shelf and wait til it 'matures' …sounds like maybe a leached half and mix it back together might work out. You can mix it with unleached Fimo though. Also FimoSoft leaches okay..

To leach, roll the clay out and place it between several clean sheets of paper. It’s best to then weight this with something heavy (putting something unporous between paper and heavy item). You can leave it this way for an hour or more, or even overnight; some of the plasticizer will have been absorbed by the paper, and the clay will be stiffer. . . .

When you see that the plasticiser has stopped staining the paper, your clay should be much easier to work with. Dotty speed up leaching, thin the clay as much as possible
.......these things also help: press it with a weight put in a warm area
also check the paper every 4 hours and if the paper is "wet," change it as dry paper helps speed the process. terry

I've had great success with cereal boxes ( after eating the cereal!). Try 2 or 3 hours at first, the cardboard really (leaches it) in a hurry. Bob

Lazy (Wo)mans Leach... I make a patty of clay and surround it with a piece of paper by folding it in half with the clay inside. I run it though the pasta machine and go to bed. When I wake up, it done. If not, I do it again and take a nap. :) Susan F.

One of the premier clay artists, Kathy Amt, always used Sculpey III for her canes. No one could figure out how she got such wonderful canes and perfect cane slices with such a soft clay. The secret is that she leached it in a paper press before using it. DottyinCA

i learned another lazy (wo)man's method from Kim Redcat. . . roll clay out medium thin to thin, slap between 2 pieces of paper (brown paper bag, typing, whatever - so long as it doesn't have any print on it to transfer to the clay), roll into a tube, stuff into a plastic grocery bag and sit on it. the plastic bag is to keep the plasticizer from getting on the chair or my rubenesque behind. after an hour, unpack, test and use or repeat as necessary. i live in a cool, dry climate so usually the first leaching is sufficient for me. Sunni

...if I need to (use it) asap... I usually make a sheet with pastamachine setting #4 and then put it on top of (some) paper and roll them together like a jellyroll cane. The paper will absorb enough in 10 minutes because the oily stuff in both sides of the paper make it easier. PöRRö
....I used the brown paper bags, print side down, cut it into strips. Then I put the clay through the pasta machine on a # 1 setting then laid it on the brown paper strips, placed another piece on top and rolled the whole thing up like a jelly roll! THEN I put a bunch of rubber bands around the whole tube, to give it extra pressure, and it took brand new STICKY translucent clay and turned it into something workable! When I opened it up a day later, the paper was totally saturated. .Leigh

I use the deli sheets for short time storage of Premo, which I find needs leaching anyways. Kathy G.

...roll the clay to about a 4-6 thickness in the pasta machine, lay it out on white paper or brown paper bags, roll them up and sit on them while you clay away; they plasticizer will leach out in about 45 minutes to an hour. The thinner you roll it- the faster it leaches....

COOLING clay, or canes ...for hot hands or weather
(stiffens soft clay)

The clays which are naturally softer when raw can sometimes be too soft for good caning, reducing, slicing or shaping.
...This is particularly the case on warm days, or if you tend to have warm hands, or if you work the clay a lot (Premo esp. is susceptible to overworking). There are various ways to deal with these problems:

Use clays which are stiffer and/or less responsive to heat, such as Fimo Classic
...have you tried using Kato Polyclay? I find it doesn't get as soft as the others. Dotty
...Premo is quickly responsive to heat, so if you use it don't overwork it (it really doesn't need it)... or cool/rest it periodically
...FimoSoft and Cernit are also softer and more heat sensitive
...(the Sculpeys may stay fairly soft no matter what).

Sculpey Flex has a liquid cystal-type platicizer. It is extremely responsive to heat. In fact, I control the softness of mine by how long I keep it near my work lamp. You probably got it too warm. I like to mix it 1:1 with my Premo anyway. Syndee

Many people find that leaching the clay will make it stiffer, even for those hot hands or hot days.
...the firmer the clay to begin with, the more heat it takes to soften it.Dotty

Letting the clay set up for awhile (even overnight) will stiffen it also.
(...when you set it aside, the molecules "slow" down. syndee)
...let it rest on the table or in a cooler area of the room (near the floor, e.g.)
...put it in the frig. or freezer for 5-20 min. or so
...if you can, let one part rest while working on another part or another piece. Patty B.
......or while mixing colors, conditioning more clay, brainstorming more ideas, clay-doodling like making Natasha beads, or even straightening up your work area, etc.

You can cool clay while you're working with it.... or while it's waiting to be used or sliced:
...can keep the clay on a cool surface
.......slabs of marble (refrigerated or not)...or "frozen" thick metal pots ...etc. (perhaps a sheet of glass or a tile)
......I have a couple of tiles to work on... I keep one in the fridge, and rotate to the other when the 1st starts to warm up .Laurel
......keep the clay (or canes, etc.) on a pre-cooled gel pack (buy at drugstore...some gel packs stay softer and more malleable than others)
......homemade rice bags (usually used for heating) can also be kept in the freezer, then used under a sheet of plastic wrap
........keep one of these in the freezer, then switch when it begins to lose its cool
.....I made my own ice pack in a ziplock bag .....with 3 parts water to 1 part alcohol
...can also place one of these cold packs under your work surface
...or place one of the cold packs in a closed container to make a mini cooler:
........I used a small insulated lunch box with a cool pack inside ...just put the clay in the "ice box" a few min's. Patty B.
.....or put the ice pack in a large open bowl right on your work table, then set a self healing mat (or tile, etc.) on top of the bowl
........that surface gets very cold so you can put clay or canes on top ot it ...and also put clay inside the bowl
........this setup keeps the ice pack from melting by "locking in" the cold air for several hours
........also, I no longer have to get up & go to the freezer to cool down cane components...just pop in bowl a few minutes. Jana

Or you can cool your hands ...or your whole room:
...a teacher told me once to keep an ice bucket with some water and ice in it and dip my hands into it now and then. Helped some. Dotty
to cool your hands, or a work surface with clay on it
...hold a cold gel pack in your hands periodically
...use an air conditioiner or even a fan
...the coolest room to work in (one side of the house will be hotter in a.m. or p.m. depending on where the sun is)

I have small electric cooler shaped much like a little refrigerator that would hold a 6 pack of your favorite beverage holds lots of clay... plugs into either your house outlets or into the car's lighter slot
...(it not only cools, but it also heats pay attention to which setting is on).
...available at Target, etc.+ stores that carry gear for fishing/hunting gear or outdoor stuff (mine is a Vector brand) will stay cold too for quite a while even after it's off..Patty B.

The "fresher" clay is, the softer it's likely to be... but it can be "advanced."
.....If your ordered clay comes too soft . . . (besides leaching), the other thing that really helps is to buy in bulk during the fall, winter or spring (avoiding the hot shipping times), and then let it sit for a "aging" one's meat or cheese. I have much better results with clay that's been sitting for a month or several...After a little aging time here in the basement studio (in a dark drawer, kept at an even temp) its much easier clay to work with. I do this with both fimo and premo, and the clays stay workable for years and years. Howard at the ClayFactory says "10 years or more" for shelf life stored correctly....we'll see. I've got old classic fimo stockpiled that is 6 years old now, and quite usuable. Sarajane
Super Sculpey . . . to select the best box for sculpting (not too soft), I had little 'tests' for the clay before I bought. ....cracks (like splits) in the raw clay were a good sign, as well as how little came off on my finger when I drew my finger hard across it. Shane

(for cold or hot effects on storage of clay or canes, etc., see Storage > Cold & Heat)
(for heat effects when having clay delivered, see Supply Sources > Ordering in heat of summer)


The hand choppers (where one hits a vertical plunger multiple times, forcing the 4-wing blade down onto the food --open bottom or sometimes in a jar) may work too
.... especially for smaller clay pieces, and for just chopping the clay into smaller bits and/or working in softeners (liquid or softer clay)

(electric choppers --food processors-- are used mainly for Fimo Classic, but can be used for any stiff or older clay.... softer clays alone may stick a bit?)

However... with Premo, FimoSoft, Sculpey, Cernit, etc., you can skip this whole processor step and just slice the slabs a little thicker than #1, then put them through the pasta machine until pliaible
.... although the newer formulation of the FimoClassic which is out now, can usually be done the same way if sliced thin enough (or use a hammer first)... unless of course, the clay is really old or partly hardened from heat or UV light exposure.

The best and fastest method I've seen for processing large amounts of clay is the method CZC (City Zen Cane) used when they gave a class at our guild and a food processor.
...Jenny's photos of chopping clay in a food processor, then putting through a pasta machine
......CZC break the clay or chop it into smallish chunks (if they're too large they get jammed just between the blade and the bottom surface of the bowl--if this happens, STOP and chop smaller).
.....They pulse or process to get it started, then let the machine run for a minute or two. This warms the clay and really helps.
..... Wait till the machine is running smoothly before adding a softener (like Diluent, Mix Quick, mineral oil, Vaseline, or another softer clay such as SuperSculpey or Premo Base) -- to avoid making the clay even stickier.
......they do not clean the bowl between colors!! ....unless they are using a *very* light color
.....They then dump the contents out on their working surface and begin rolling over the pile of crumbs with an *18"* acrylic roller (I bought one from them and have never regretted it--the extra length adds a tremendous amt. of torque for the extra inches and makes things go much faster, especially for a short person).
.....When the clay is almost to the #1 setting size, they begin rolling it through the pasta machine. (They also turn the clay over a few times while rolling, just like pie dough.)

I still use my little mini food processor that way for doing smaller amts. of old-hard or Fimo(Classic) clay as needed, even though other clays don't need it... even the newer FimoClassic can be conditioned only in a pasta machine
.....but I dump it out onto a tissue, then squeeze the tissue with my hand to compress the bits before flattening and putting through the pasta machine. Diane B.
...Cindy P's online video lesson on conditioning FimoClassic in a small-med. food processor, after cutting across bar to create strips, then turning and cutting across the strips to create small cubes... she adds a bit of Diluent as well (also runs it through a pasta machine a few times at the end)

. . .pulse the mini food processor until it makes tiny crumbles and begins to cling together. I would advise against using more than 2 oz. at a time as it might overload the machine.
...Take the crumbles out of the bowl and dump them in a plastic bag. The heavier quart size freezer bags work really well.
....After the clay is in the bag, drop 3 or 4 drops of the Diluent (soon to be called Clay Softener) onto the clay. Close the bag and begin working the clay with your hands on the outside of the bag. This will prevent your hands from getting so oily or stained.
....Once the clay clings together really well, turn it out onto your work surface and roll it with your acrylic rod or brayer until you have a rather rough slab.
...Then on the thickest setting of you pasta machine, begin rolling it through. Folding and rolling until it is a nice smooth sheet.
....If the clay is still very crumbly when you first put it through the pasta machine, work small amounts of the clay in your hands until it becomes warmer and sticks together well. Patty B.

I tried the hammer method today and found it very satisfying , if somewhat noisy
.... (see above under Beating to see many methods of hammering on the clay to soften it)

I use the mini food processor and a little softener to grind up the clay
.... then I pour it out onto a sheet of plastic wrap and pound it with a small meat tenderizer (mallet)'s the weight of the pounder, not the force that does it. This makes it into a smaller, compact form
....I cut off sections to run thru the pasta roller . . .

. . . in the food processor the larger the "curds" the softer the clay.
.....(in the food processor) Look at the size of the crumbles. If they are very small, the clay is usually too dry to go through the pasta machine without crumbling even more. If they are large like large curd cottage cheese, the clay is going to be too soft. You want them somewhere in the middle and when you touch them they should be slightly tacky.
. . . pull out the blade and scrunch all the crumbles against the side of the bowl.

What are the "do nots" for conditioning in a food processor? Lori
...Soft clay, if processed all by itself, will glom together fairly quickly and can overload the food processor motor. When processing polymer clay, keep an eye on the size of the nuggets. ~During the initial processing phase, the chopped clay resembles little chunk or nuggets like Grape Nuts. As the clay warms, those nuggets usually get larger and larger. This is usually a good time to stop and dump out the clay. When the clay shows signs of trying to form one big ball, you've gone just past where you should. If the clay nuggets never grow larger, you've got stubborn polymer clay; maybe very old, maybe partially cured. Adding some soft clay (like Premo, Cernit or Sculpey III) or Quick Mix or oil/grease (mineral oil, baby oil, vaseline) and processing that mixture will help you figure that puzzle out. If after processing and manipulating by hand you still have some hard pieces, let the clay still for many hours to let the softening agent penetrate and try conditioning again. If this doesn't work, you've got clay where portions of it were partially cured.
...To make things a bit more complicated, the best time to stop processing depends on the motor's power. For example, if you use one of those mini processors, their motors are small so you can usually run the clay longer, because the speed usually never creates enough force and friction to cause problems in the clay. The standard size food processors are a different story, though. They can continue to chop the clay while warming it up to the point of curing spots in the clay. This can take 5 minutes or more, a time frame you're not likely to exceed (the racket is louder than the pasta machine motor!), but it's something you'll want to keep in mind with the big boys.
Regardless of the size of the food processor, it's a very, very good idea to manually chop the clay into small pieces and add that to the bowl. The less work you do, the more work the motor has to do and the quicker it wears out.
...I used my little mini Black and Decker to chop preClassic Fimo for 6 years! And then the motor didn't burn out, the plastic shaft thingie finally crumbled. So I went and got me another little Black and Decker. I also have a standard size Hamilton and Beach I found at a thift shop. It's quite a noise maker, but it was cheap and does the job quite well. Desiree
(Also, *never* fill any food processor more than halfway full at one time; it puts too much strain on it and can burn out the motor or strip the threads from the blade spindle.)

I plopped some soft, conditioned clay in with the little tiny crumbles and turned it on.... bad me! The blade broke off and flew *through* the side of the (Lexan) bowl, bouncing off the wall behind it and spraying clay crumbles everywhere. I later found out on one of Maureen Carlson's videos that putting soft clay into unconditioned clay is a bad thing... .Elizabeth
...Oh Elizabeth! Scar-ey! I've never heard of this. l add softer clay all the time to the food processor, though I do pull it into smaller pieces and either add them one at a time through the shoot, or from the beginning with the small clumps of harder clay. I've never even heard the engine strain from this treatment. I'm wondering if you did something a little different from what I've done--if so, I want to know about it and avoid it!!! (Since you seem to add *more than one block of clay* to a *small* processor, plus more soft stuff, I wonder if that’s just too much strain?) I also wonder if it's possible that your machine was already stressed near a breaking point and this was the straw that broke the camel's back? ( I do know I killed one small chopper by putting in pieces of clay that were too big, and also not stopping the machine and rearranging the pieces if the blades stalled while it was going!) DB

<I can blend mineral oil with dry, crumbly clay to make it soft again?>
....Yup. (they’re all petroleum products . . .?) Mineral oil (no more than 10-12 drops per 65 gms or a block of Fimo). A little goes a long way but if you needs tons of mineral oil, you've got a problem that's more serious than just stiff clay.
Vaseline works too, but produces a slightly different effect.
. . Clarification: Don't just dump 10-12 drops of oil in at once. Add a few drops, after running the clay through a couple of minutes of food processing. If the chunks are still tiny, add a few more drops. So, start off with a small amount, gradually increase. Remember it is far easier to add oil than remove it, so go very cautiously. And for really, really old stiff clay, it can take a few hours for the oil to soak thoroughly soak the clay particles. Be patient. Condition the clay with a little oil, stick it in a plastic bag, set it aside under a warm lamp or a warm kitty or something, get back to it after a while, add more oil if necessary... Desiree
However, I prefer the thicker, laxative-type mineral oil over regular mineral oil (baby oil only?). Desiree

Arlene Thayer : "Not only does a food processor warm the clay but aids in the conditioning. The food processor should be dedicated to this purpose only and not used for food preparation. . . If the clay feels dry and won't press together easily, add one or two drops of mineral oil, vegetable oil or Sculpey Diluent (a plasticizer in a bottle) and run the processor again.
....Too much oil
, however, can make the clay sticky and too soft.
....Improper kneading can cause the finished product to crack or have a porous look.
Colors can also be mixed together using any of these methods.
MixQuick is a softening medium developed especially for FIMO to make it more workable. Adding 1 part to 4 or 5 parts is the general rule."

Conditioning FIMO: Remember... it'll NEVER be as hard again as it was right out of the package!!! It may stiffen up from use to use... but once it's been conditioned, it'll get soft much easier the next time you pick it up

Firstly... chopping it up into tinee pieces helps the process for some reason. Whether you do it with a blade or throw it in a food processor. I got a food processor at a yard sale for $5. DON'T use it for food once you've used it for clay. I like the processor because, if you're mixing colors, it distributes them so evenly.
Secondly... I add a 1/2oz of white & a 1/2oz of MixQuick to each 2oz's of Fimo. Chop it up all up together & throw it in a baggie... then just condition handfuls of it as you need it. It'll condition easier for having sat in the bag a little while with the mixquick & white.
The MixQuick is a clay softener. I've never had to use more than the amount I just mentioned. If you use too much you offset the reason you use the Fimo... finished strength.
The white is generally the softest of the colors and will help soften somewhat too. It will also help keep your colors bright as they will darken just a bit in the baking. It will ALSO act as a visual guide to tell you when you're done conditioning. Also... sitting on the bag and prewarming it a bit will be a MAJOR help! I also work under a light for extra warmth.... and sometimes pull the light down to warm my work suface.
Thirdly.. take a handful out of your baggie... lay it on your work surface and pack it together.
Start to roll it, on your work surface, using the flat of your hands... squeezing it can be hard on your joints. It'll still fall apart, just pack it back together and continue rolling it. Be patient... and don't worry about little bits that lay on your surface, you'll roll them up later.
Once it's holding together somewhat, pick it up and roll it back and forth in your hands... like starting a fire with a stick... the friction and warmth from your hands will do the work for you!!! Fold it in half and twist it, as it lengthens out, and continue rolling... until it's blended. Once it's holding together, you can roll it over your work surface to pick up all the bits and pieces. Joanie

There are many additives you can put into the clay to make it softer, but Mix Quick will incorporate more quickly into a smooth elasticized piece of clay

Fimo... I can't work with it unless it has been treated in the Food processor with 20% transparent clay (translucent) added it to
.....It stays soft forever this way and needs very little prep time-

The easiest way to clean your food processor and pasta machine between colors is to use plain white sculpey. It's really sticky and will grab all the crumbs of your previous color. It works even better once the piece gets a little dirty and less sticky.
...Formula 409 works like a dream on the food processor bowl and blade, etc.
ust don't use 409 on your pasta machine. Its chemical makeup tends to react with that form of steel, frequently causing more streaking. Desiree
...other people shake out the larger crumbs, then give a quick wipe with alcohol
...actually, City Zen Cane never clean out their bowl at all... they feel it's not necessary because any tiny bit of color will get incorporated into the next color, and since they tend to process a lot of clay at one time that amount is insignificant . . . they also do more caning and less sculpting, so any tiny change in the color wouldn't show up by the time the cane is reduced anyway. Diane B.

A problem I had with my mini chopper (don't remember which brand) was that the plastic housing (hexagon shaped) which held the spindle wasn't strong enough, and got more or less ground down until it couldn't really grab and rotate the spindle if there was much pressure at all. ...I've heard that some brands have a metal housing that can't do that. Diane B.

When shopping for a mini, look for a design where the motor spindle has a cross pin that locks into the blade column. This assures the blade will turn under greater pressure. Black & Deckers are like this. There are other brands with similar designs, but after my mini B&D's performance, I'd recommend B&Ds. Earlier I mentioned giving the motor a chance. This means finely chopping the fimo by hand first. The more your chop the clay before hand, the better the chances of keeping your machine in operational condition. Like I said, mine lasted 6 years. If you decide to go for a standard food processor model instead of a mini, you'll have a more powerful motor and won't have to worry about the spindle design. However, it still helps to pre-chop the clay. Advantages of a mini - smaller footprint, lighter weight, handles small amounts of clay much better, a little quieter... Advantages of a standard - more power, handles larger amounts of clay, readily available in thrift shops for a good price. Hope this helps Desiree

I had small Cusinart burn in in less than a year. Now I use a Sunbeam Oskar mini processor... and the difference is incredible. It makes mincemeat of the clay in half the time the other one did... and with no straining. I feel a lot better about this one lasting... but time will tell. Seems to me I read somewhere that Mike Buessler users the Oskar too.
My Oskar was a honey but the blade broke. I've had two of them do that, now. Can you get new blades?

Make life easy...get 3 food processors at thrift stores for $5 to $10 each, using one each for black, white, and the 3rd for color. Hamilton Beach dual speed's are quiet, but the GE's are easier to use when doing ALOT of clay. G'luck

I have a small Black & Decker food processor... it works great with fimo and firm clays but once I tried some premo that was fairly soft and it stripped the center of the blades (the hole area that the gear slips into). Helen P.

Get more than one food processor bowls . . . keep one for lights, one for darks and one for translucent. Helen P.

before I got my mini-process or, I used to use a food grater for raw know the kind--mom/grandma used to grate potatoes on them for hashbrowns? much more portable and just as easy to clean (wire brush for the inside, with a generous helping of "Dawn" detergent.


I put the clay in my meat grinder as roughly 1" chunks and crank it through with a few drops of mineral oil, Diluent, or fresher clay added. Mostly this is bulk super sculpey, but I have also put through some old, crumbly Promat mixed with the Super Sculpey, and done some hard Fimo by itself. isn't as hard as all that to crank. The smaller you break up the clay, the better, though...It all comes out like new, soft clay in one or two passes through.
Once out of the meat grinder, I've been flattening it, and running it through the pasta machine a few times, then popping it into zip bags.
The smaller(grinder) unit the better. Mine is a number 3 and I understand they don't much make them smaller than #5 any more wouldn't want to go bigger anyway). At least Universal doesn't.… I think the number refers loosely to the distance between the hopper and the plate, but I could be wrong.(
. . .The one I use has got slots instead of holes, rather like the one mother used for relish. I got it for a buck at a thrift store, but lost the handle and had to order a new one. Still cost under $5 total. It's clamped to a counter right next to my pasta machine; close enough that I take out the pasta machine's handle when I run clay through the grinder.
The effect is amazing. The stuff comes out about as soft as new clay, ready to hand condition quickly or run through a regular pasta machine. Really stubborn stuff can take a second trip through the grinder with or without more diluent. .... I use a lot of clay for my spindles and figures and this lets me condition large amounts much more quickly. ...What I particularly appreciate about the meat grinder is not only its ability to do these large quantities in larger chunks, but the peace and quiet of the hand crank tool. . .
. .
.Meat grinders are also much easier to clean. They're designed to disassemble easily so you don't have any bits of meat lingering within to culture bacteria. But usually I just put a little (SuperSculpey) through between colors and use the resulting mixture as scrap clay. The smaller the capacity, the less clay remains in the augur, but no one needs anything bigger. Halla
....So far the lowest prices I've seen for new ones have been in the Northern Tool Catalog: --no affiliation. Oddly, food processing things tend to be under sporting goods in their on-line catalog. Halla

Or look for them online, on eBay, or at garage sales and thrift shops...

some online grinders... search for "meat grinder":
-- (a #2 and a #3 size)
--Yahoo . . . 3 styles & prices, beginning at $20
--K Mart (online) $26? (long barrel one . . . okay?) Eastman # 10 Compact Manual Meat Grinder Item no: 991722
-- ??

I use and love one of those old hand-cranked food choppers called a Mouli grater... you can buy them new, or find them at yard sales (or in your kitchen or your mom's) . . .Even when i use my electric chopper, I always run it through the Mouli first to save the motor of the electric chopper. Rae
...mouli grater: a French rotary grater that is perfect for grating small amounts of foods like cheese, chocolate and nuts. The hand-held unit consists of two sections with hinged handles. The end of one handle contains a food hopper with a grating cylinder and a crank for rotating the cylinder. The other section has a rounded surface that acts as a clamp, pressing the food to be grated into the grating cylinder. The hinged handles are held in one hand and squeezed so that the food presses against the grating cylinder. Meanwhile, the other hand turns the crank, causing the cylinder to rotate and the food to be grated.

You can also use large or tiny, regular, hand held metal graters to grate hard clay, to make small bits, or to make speckles for adding to clay (as with faux jade) or on top of sheets for visual texture.

That's true with the electric version of a meat grinder too. I ground up a few pounds of leftovers today, and you should always be careful to cover the chute where you add chunks while it is whirling, because sometimes things fly out...Sarajane

Also, always sift your leftovers carefully before adding to the processor and watch out that foreign matter, like wooden beads or pieces of paper, do not get mixed in there. Sarajane


( avoid having clay arrive hard when delivered by mail order, see Supply Sources > Ordering clay in the heat of summer)

Most of the clays (except Sculpey, Super Sculpey, and Sculpey III) will stiffen after sitting awhile, even after being conditioned. This is true for canes made from them too.
Depending on how long they've been sitting and if they were wrapped or not, they may need to be restretched and rewarmed briefly to bring them back to maximum suppleness (if they crack at the top of a bent log, they need it).
This will be most true of FimoClassic, I think.
Most people condition only as much clay as they need for the moment unless they're doing production work, but there will often be leftover clay.

If the clay will be sitting for awhile (more than a few days?), it will stay most supple if it's wrapped in plastic wrap or containers (see Storage for which plastics are ok).
...some people like to store their clay in sheets and feel they can use them as is (maybe they warm them briefly with a heating pad, etc. first?), but even using waxed paper will tend to "dry" sheets out.
... Sculpey (Sculpey III translucent, or Super Sculpey too?) is the only one that has 2 plasticisers, and one of them is water soluble
.... since it has some water in there --more than the other brands-- maybe the flat sheets dry out a bit AND cool off ...that's my theory. Sarajane

My solution is to compress and compact (bash) the clay (while it's still in the wrapper) with a rubber mallet on all sides until it is a smaller cube shape... then I remove it and roll into a log to begin conditioning it (....may work esp. well for clays that get crumb-y during conditioning, like Fimo). Garie and
....I condition my polymer (particulary Fimo) with a heavy wooden mallet. Hitting it and turning over and over. Has worked like a charm for me for a long time. You don't have to hit too hard either. . . . something about that gets the plasticizer moving. Lori
(...see other ways to beat on hard clay to soften it, especially for crumbly or hard clay --perhaps in a plastic bag with liquid clay or Diluent-- above under Beating)

(when using a food processor) During the initial processing phase (of food processing), the chopped clay resembles little chunk or nuggets like Grape Nuts. As the clay warms, those nuggets usually get larger and larger. This is usually a good time to stop and dump out the clay. When the clay shows signs of trying to form one big ball, you've gone just past where you should. If the clay nuggets never grow larger, you've got stubborn polymer clay; maybe very old, maybe partially cured. Desiree

(I used my ) upright knucklebuster grater, the kind grandma used to use. Duh. Boy, does that make short work of stiff clay! Grate that stuff into a pile, grate some mixquick onto it and mix it up... five minutes to nice pliable clay.. I put the clay on my palm just where the fingers begin, and stroke it against, instead of holding it to, the grater. HOW I learned that is best left untold.... ;o) kelly

Adding some soft clay (like Premo, Cernit or Sculpey III or a translucent) or MixQuick or glycerin, mineral oil, baby oil, vaseline-- and processing that mixture will help (soften hard clay) . If after processing and manipulating by hand you still have some hard pieces, let the clay sit still for many hours to let the softening agent penetrate and try conditioning again. Desiree
....see many MORE DETAILS on these above, in Additives

I pulled out my SculpeyIII a couple of months ago -- it had been sitting in storage for up to two years, and some of the blocks were hard as bricks and crumbly (unusual for Sculpeys!). I bought some Sculpey diluent and sliced down through the "bricks" to cut them into four or five layers. I put three or four drops of diluent in between each layer, stuck them all back together and put them in a ziplock bag. Last week, all that clay was like new! It felt hard, at first, but, it smoothed out just fine in the pasta machine without any crumbling, and didn't seem to show any sort of discoloration or cracking after baking. You can't tell what is old clay and what is new in the finished pieces. So, if you've got the time to just let it sit, that would be my choice for bringing it back into condition.

I bought a big bottle of baby oil (it's a slightly lighter petroleum fraction than mineral oil, so it mixes better). I would chop the dried-out clay with a knife into little chunks, drip oil on it , and put it in a soft plastic container (Tupperware, etc.) and let it sit for a couple of days. Then, depending on how it's doing, I can put it in a food processor, or just pasta machine-squash it to a lovely, workable texture. If it's a little too oily, just stick it onto typing paper, which will slurp up any extra (leaching).

You can get your clay to come back to life after it's (really hard) . . . I coat the block (or chop it up depends on how quickly you need your clay) well with TLS and put it in a container (baggy works) and let it sit for up for a few hours to a few days. It will soften right up. Marie Segal told us in a class yesterday that this even works with clay that has been baked (?!?). Robin

If I have clay that is old and crumbly (not cured, just old and dry), I crush it into as many little pieces as possible. I put the pieces in a container, add a glob of Vaseline, and mix it all together. I seal the container overnight. The next morning, I throw it in the food processor and pulse it a few times to ensure a thorough mixing. I end up with a soft mess that, when kneaded and run through the pasta machine a few times, makes perfectly usable clay. Only once did I put in too much Vaseline, and that problem was solved by letting my glob sit between some sheets of paper for a few hours for the excess oil to leach out. Celeste

using liquids to soften even baked clay...

. . . Marie Segal told us in a class yesterday that this TLS method even works with clay that has been already baked . . . coat the block (or chop it up depends on how quickly you need your clay) well with TLS and put it in a container (baggy works) and let it sit for up for a few hours to a few days. It will soften right up.. Robin
...Slice the block into 1/4" slices. if its really dry (look at it) dab it with Sculpey Diluent. Compress the slices by rolling and bearing down with your acrylic rod until it's just a bit thicker than the thickest setting of the pasta machine; roll it through; reset to a thinner setting, then roll through (don't fold); reset and roll until you are at a medium thin setting. roll through, fold and roll, rold and roll. the thinner setting really speeds up the process (fimo is very pressure sensitive, that's why it reduces so well. heat and pressure together. i condition my clay really fast! ) (then fold & roll?). Donna Kato

.... I just thought of something kinda off the wall. Old polymer clay usually benefits from an infusion of plasticizer, quick Mix, mineral oil etc. The problem is forcing the softening agents into the clay. . . . I have one of those vacuum & seal food storage machines. (I highly recommend them, BTW). One of the features is quick marinading because in a vacuum the liquid marinade is much more quickly absorbed into the meat tissue. So instead of marinading meat for hours or overnight, it only takes 10 - 20 minutes. I'm wondering if after chopping up the stiff raw fimo, if using that machine to "marinade" the clay in a little oil wouldn't speed up the softening process a bit. The same basic process (without doing the chopping) might work on old stiff canes as well. Hmmmm.... Desiree

If you don't have one of these machines, you can get a lesser version of the same result by using a heavy zip-type bag, and sucking out all the air you can with a straw before zipping the last little bit (since this is polymer, don't inhale :-) . . . ) DB

...*So making an almost perfect vacuum with ziplog bags is easy and you don´t need to inhale anything. Put your (clay, or clay/mineral oil, or canes, or clay sheets --or food) into the bag and close almost half of it. Find a little bit bigger container than your bag and fill it with water. Put the bag under the water (the air-hole should not go under water), and let the water (force) the air out of the bag. Seal and take out of the water. Dry with towel. You have to try this before you believe it is almost as good as any vacuum-bag machine out there. And yes, this is the method I use constantly with food (to help avoid freezer burn, and loss of vitamins, etc.). PöRRö


There are various ways that air or moisture can get into or under clay (especially into sheets) which may show up as bubbles or lumps during pasta machining, or baking
.... air bubbles can show up immediately or not until the clay is heated

Some of the causes have to do with:
the way the clay is conditioned or trapped clay under pasta machine scrapers pulling on sheets, particular type of clay or soft stretchy clay, particular type of box or bar of clay you happen to get, covering or layering clay sheets trapping air, not letting clay rest before baking, moisture from hands or white glues creating steam bubbles, etc.... here are just a couple of suggestions:
running your clay through the pasta machine at progressively thinner settings (without folding) can help avoid, or get rid of, bubbles. LynnDel
...letting clay rest before baking can help make internal bubbles go away for some reason
...leaching the clay may help

but MOST of the info (of all kinds) on air bubbles is in Pasta Machines > Problems > Air Bubbles

...for info on air bubbles in liquid clays, see Liquid Clays
...also see plaquing in Translucents > Plaquing


I have heard that if you want far stronger clay –and more flexibility-- (with Fimo, small items.. . & others clays/sizes?), you should bake at 325 for 10 minutes; the bonding of applied pieces will also be excellent. (325 is still below the danger temps of clay.) DB

Otterfire: …Daphne Seaman told us about it, I think she said she took a class from Peir and she was the one who suggested this (if i am wrong about the class correct me please). She said that she uses 2 thermometers in her oven. she places her peices in cold and then turns the oven to the reqired temp. once it reaches that temp she startes a timer and after 15 minutes kicks up the temp to 300. THE INSTANT that it reaches 300 degrees, she shuts off the oven. that final burst of heat evidently bonds the clay better, and i have to attest to it...they are correct.
in the experiment i did under jel rollers, i used sculpy and premo....and the premo is very bendable to begin with, but i can totally roll these sheets up....and no tearing. ALSO, the sculpy has a lil more give, it will still snap if you force it very far, but, it has more give (IMHO) than that sculpy that hasn't been kicked up.
I will have to admit i was very nervous about going up to 300...but i didnt even get any singe on the bottom of these test peices and i laid them straight on an aluminum cookie sheet...otterfire

I think Lynda Struble was the first person to advocate the ice water plunge for stronger clay (and clearer translucent) . Sue Heaser published an article about what Lynda said in the British Guild newsletter in 1998, and clayers all over UK have been using it ever since. Lynda is a plastics chemist and a fantastic polyclay sculptor as well. DB

See also the addendum which has the results of many tests performed on the clays to determine their relative strength and flexibility (before Kato PolyClay was introduced though):

MISC. re conditioning

Is it okay to mix clay brands?
Years ago, when I was low on Super Sculpey, and in rush to finish a sculpture, I used Cernit, blending it with Super Sculpey at a one to one ratio. That piece is now more than ten years old, and shows now sign of decomposition. I question the validity of the decomposing (baked clay) doll tale --especially that it occurred because two disparate polymer clays were mixed together. So many artists underfire Super Sculpey and Super Sculpey blends to prevent scorching. As a result the clay is more crystaline, brittle because it is underfused. I await what the polymer chemists have to say. Katherine Dewey
.....Clay brands can all be mixed together, as far as I can tell. The main caveat is that when caning, *any* clay mixes, or colors mixes within one brand for that matter, must result in the same consistency or the cane will distort more easily when reducing.

I've done a number of kids' classes and some adult ones where we didn't have time to condition everything and still get much claying done. In those particular cases, I did all the conditioning and mixing of colors before class (then rolled into logs, which I cut into 3/4" cubes because I needed to control the amount they used). I tried to do enough clay in one session to last me for a lo-o-ong time (for kids, that was generally 36-50 kids making several things over 6 weeks). I had lots left over for later classes using this method.
....Anyway I dedicated a number of hours on one day to doing the whole thing using my dedicated food processor, plus drops of Diluent (or Vaseline) especially for the older/harder stuff. I ran through the basic colors (usually yellow, orange, red, purple, blue, and green... or just the 3 primaries) one at a time light to dark. I also made various tints, tones and shades by removing part of a color after processing and adding white, gray, black, or the complementary color to parts of the original batch. I also tried to get a number of tertiaries by mixing the originals together. It's impossible to make all the colors, of course! but I tried to have lights, darks and mediums in a variety of rainbow colors and neutrals so their cane making in particular could be successful (for example, I'd let them choose a light, a medium, and two darks of the same color for making a cane ... or a light plus a dark or med. for making a spiral cane).
...For winter classes where the clay would be too cold without reworking it, just before leaving I'd put the clay in a cardboard box which I then put on an electric warming tray for awhile, or I'd place heating bags or pads of various kinds on top, then cover with towels/blankets to insulate, and cart to class. Later I sometimes used a "meat defrosting tray" for my own work... it just sat on my work area with clay on it; after warming, those things really hold their heat . By class time, the clay was fairly soft and pliable (sure wouldn't do that with Sculpey though!).
...You could do the same thing without totally conditioning the clay by cutting the bars into thick slices or running through a food processor before putting in the box. Having something to cut thick slices with from the larger (or small) bars when you're doing a lot of them at one time can be helpful. I have a JASI stand-type cutter which I don't think is being made any longer (though you can rig up something similar... see
Cutters&Blades, under "Stand Cutters"), and I also have a Dove cutter ... Diane B.

(see Scraps and see Canes--Old for some things you can do with old, hard canes or clay)

(see aso Pasta Machines, )