Before using polymer clay, for whatever purpose, it is important to condition the polymer clay before use. This means working the polymer clay until it is soft and malleable, and of the same consistency throughout. When a block of polymer clay is first opened, it is stiff and tough to work with. It may crumble when it is rolled or shaped. When the clay has been conditioned, it will be substantially softer and less likely to crumble. The length of time it takes to condition a piece of polymer clay will depend on many factors, such as the brand, how old the clay is, and the background temperature.
How to Condition Polymer Clay
Polymer clay can be conditioned in many ways. It can be conditioned by hand, with a polymer clay pasta machine or very old or hard polymer clay can even be conditioned in a craft dedicated food mixer. Many polymer clay artists develop their ways of conditioning polymer clay, depending on the results required. The two main methods of conditioning polymer clay are by hand or using a pasta machine. This will produce soft and well-conditioned polymer clay that is suitable for many projects.
Condition Polymer Clay by Hand
To condition polymer clay by hand, it is best to work with no more than a two-ounce block at a time. Work the clay by kneading it and twisting it, ensuring that the entire piece is manipulated. When it is fully conditioned, it will be soft to the touch. The warmth of your hands will speed the process, and warm polymer clay takes less time to condition than cold polymer clay.
Condition Polymer Clay Using a Pasta Machine
A pasta machine makes conditioning polymer clay easy. The clay is fed through the pasta machine and folded several times. The polymer clay is fed through the pasta machine folded edge first to help to reduce introducing air bubbles into the clay. The clay will be fully conditioned after 15 or so rolls through the machine.
Condition Stiff Clay
Very stiff polymer clay can be mixed with a soft block of clay to help soften it. A light brush of mineral oil may also help to soften stiff clay.
Condition Soft Clay
Clays that are very soft and sticky can be stiffened by leaching some of the plasticizers from the clay. Roll the soft clay into a sheet and place this between two sheets of absorbent paper for about half an hour. This will absorb some of the plasticizers and make the clay stiffer to work with. This should be done with caution as the removal of plasticizers can result in the clay being brittle once cured.