How long does polymer clay keep?
Polymer clay, being non-volatile, can be stored for months or years. Exposure to air will not hurt it, although it’s best to keep it wrapped for protection from dust and lint. Unlike true earth clay, polymer clay does not contain water that can evaporate. The main danger to polymer clay is from excessive heat or ultraviolet light; these can partially fire the clay, making it unusable. Over time, the plasticizer that keeps the clay soft can also leach out, leaving hard, crumbly clay. A common rule of thumb is that clay can be kept at least a year, sometimes for several years. Your clay will last longer if you keep it away from sunlight and heat.
