- POLYFORM-Sculpey Clay Softener. Rescue old unbaked clay! This softening agent will improve the texture clays that have become dry and crumbly. Use sparingly by adding a few drops and kneading into clay until it softens. Also great for removing fingerprints from clay pieces. This package contains 30mL/1fl. oz of liquid clay softener. Conforms to ASTM D4236. Made in USA.