Polymer Clay: Conditioning

Polymer clay has to be conditioned prior to use. Conditioning in this case means thorough mixing. It is required because the composition of polymer clay changes slightly during its storage due to evaporation and leaching of its plasticizers. You will want to have the same amount of plasticizers in every piece of clay you are using otherwise the clay will behave differently during sculpting and baking. Also, the clay becomes more pliable as a result of conditioning. Depending on the brand, polymer clay will be more or less stiff at the beginning, and it gets softer as you condition it (more on differences among the PC brands).

To make conditioning easier, start with warming up your clay. The gentlest way of doing it is to carry the clay in your pocket for a while. If you do not need the entire brick of clay for your project, slice a piece of clay about 1/8 " to 1/4 " thick and put it into a zip-lock bag, then put the bag into your pocket for at least a few minutes. Some people prefer sitting on their clay to warm it up, which is also an option. Alternatively, you may try to warm the clay on a sunny windowsill, but keep a close eye on it and leave the clay there for no more than a few minutes (you do not want it to start curing yet, right?). You are ready to start conditioning your clay once it feels pliable. Expect to be able to squeeze the clay with some effort. It shall feel similar to a therapeutic rubber ball, but not like play dough. To condition polymer clay by hand, simply mix it and squish it with your fingers. You may want to roll it into a log between your palms, fold it in half, and then roll again. The smaller the piece of clay you are conditioning, the faster it will soften up.

Alternatively, you may want to use your pasta machine to condition your clay. Do not forget to flatten the clay to at least 1/4 " thickness before you put it though the pasta machine for the first time, otherwise the machine rollers may become misaligned. Use the highest (the thickest) setting on your pasta machine. Roll a sheet of clay, fold it in half, and then roll again on the same setting. Repeat it as many times as needed to soften the clay. Make sure to feed the folded part first into the machine to avoid trapping any air in the clay. Trapped air bubbles tend to expand during baking and may cause bulging of the clay surface.

Some people like to use food processors to condition polymer clay. It works best with significant quantities of clay, especially if you are using lots of the same color polymer clay (as it may be difficult to clean). Also, be advised not to use the same food processor for clay and food. You may want to read more about safety precautions while working with polymer clay.

Sometimes, the clay is so stiff, that it seems impossible to condition it following the instructions above. This may happen if the clay is too old or was stored at higher temperatures and started to cure. To soften this clay, consider adding some Sculpey Clay Softener (do not worry - although it is called Sculpey, it will work for any polymer clay). This product may be found in craft stores next to polymer clay or on-line (about $2.50 for a small bottle; you will only need a few drops of it per small package of clay). You may substitute it with a few drops of Liquid Clay (this is the method I prefer since Liquid Clay is a more universal product than Clay Softener and may be used for many other tasks). Liquid Clay is available from Sculpey and Kato, about $5 per 2-oz bottle). If you do not mind changing the color of your old clay, you may try mixing it with some softer clay (such as original Sculpey (white) or Sculpey III). Whatever you use, add small portions at a time and mix thoroughly.

Fresh, out-of-package clay may sometimes present an opposite problem and be too soft and squishy for your project. People with hot hands and in warmer climates seem to encounter this problem more often, so for them refrigerating the clay and periodically washing their hands in cold water should help. Another idea is to reduce the amount of plasticizers in clay. To do this, place a block of un-wrapped polymer clay on a piece of paper and let it sit for a few hours. You shall see an oily stain around the clay indicating the leaching plasticizers. If this still does not work for you, consider switching to stiffer clays (such as Kato).

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				Polymer Clay: Conditioning Polymer clay has to be conditioned prior to use. Conditioning in this case means thorough mixing. It is required because the composition of polymer clay changes slightly during its storage due to evaporation and leaching of its plasticizers. You will want to have the same amount of plasticizers in every piece of clay you are using otherwise the clay will behave differently during sculpting and baking. Also, the clay becomes more pliable as a result of conditioning. Depending on the brand, polymer clay will be more or less stiff at the beginning, and it gets softer as you condition it (more on differences among the PC brands). To make conditioning easier, start with warming up your clay. The gentlest way of doing it is to carry the clay in your pocket for a while. If you do not need the entire brick of clay for your project, slice a piece of clay about 1/8 " to 1/4 " thick and put it into a zip-lock bag, then put the bag into your pocket for at least a few minutes. Some people prefer sitting on their clay to warm it up, which is also an option. Alternatively, you may try to warm the clay on a sunny windowsill, but keep a close eye on it and leave the clay there for no more than a few minutes (you do not want it to start curing yet, right?). You are ready to start conditioning your clay once it feels pliable. Expect to be able to squeeze the clay with some effort. It shall feel similar to a therapeutic rubber ball, but not like play dough. To condition polymer clay by hand, simply mix it and squish it with your fingers. You may want to roll it into a log between your palms, fold it in half, and then roll again. The smaller the piece of clay you are conditioning, the faster it will soften up. Alternatively, you may want to use your pasta machine to condition your clay. Do not forget to flatten the clay to at least 1/4 " thickness before you put it though the pasta machine for the first time, otherwise the machine rollers may become misaligned. Use the highest (the thickest) setting on your pasta machine. Roll a sheet of clay, fold it in half, and then roll again on the same setting. Repeat it as many times as needed to soften the clay. Make sure to feed the folded part first into the machine to avoid trapping any air in the clay. Trapped air bubbles tend to expand during baking and may cause bulging of the clay surface. Some people like to use food processors to condition polymer clay. It works best with significant quantities of clay, especially if you are using lots of the same color polymer clay (as it may be difficult to clean). Also, be advised not to use the same food processor for clay and food. You may want to read more about safety precautions while working with polymer clay. Sometimes, the clay is so stiff, that it seems impossible to condition it following the instructions above. This may happen if the clay is too old or was stored at higher temperatures and started to cure. To soften this clay, consider adding some Sculpey Clay Softener (do not worry - although it is called Sculpey, it will work for any polymer clay). This product may be found in craft stores next to polymer clay or on-line (about $2.50 for a small bottle; you will only need a few drops of it per small package of clay). You may substitute it with a few drops of Liquid Clay (this is the method I prefer since Liquid Clay is a more universal product than Clay Softener and may be used for many other tasks). Liquid Clay is available from Sculpey and Kato, about $5 per 2-oz bottle). If you do not mind changing the color of your old clay, you may try mixing it with some softer clay (such as original Sculpey (white) or Sculpey III). Whatever you use, add small portions at a time and mix thoroughly. Fresh, out-of-package clay may sometimes present an opposite problem and be too soft and squishy for your project. People with hot hands and in warmer climates seem to encounter this problem more often, so for them refrigerating the clay and periodically washing their hands in cold water should help. Another idea is to reduce the amount of plasticizers in clay. To do this, place a block of un-wrapped polymer clay on a piece of paper and let it sit for a few hours. You shall see an oily stain around the clay indicating the leaching plasticizers. If this still does not work for you, consider switching to stiffer clays (such as Kato). More Tutorials Up \| Down \| Top \| Bottom