AMACO-Plast-I-Clay. This is a non-toxic; non-hardening; plastic modeling clay at an economical price. Helps children learn and grow by encouraging creativity and self expression. Clay is clean and safe for all ages Kindergarten through 12th grade and stays soft & pliable when stored in a sealed plastic bag. Colors blend easily. This package contains four 4oz/113.5g blocks. Clay conforms to ASTM D4236. Available in a variety of color combinations: each sold separately. Made in USA.