Keep polymer clay sealed in an airtight container. This will help to prevent the clay from drying out and becoming brittle. If you are storing clay for a long period of time, it is a good idea to place a piece of wax paper between each sheet of clay to prevent the clay from sticking together.
Condition polymer clay before using it. Conditioning clay helps to soften it and make it more pliable. This is especially important if the clay has been stored for a long period of time. To condition clay, simply knead it until it is smooth and pliable.
Polymer clay can be stored indefinitely if it is properly cared for. By following these tips, you can keep your polymer clay in good condition for many years to come.