Van Aken Kato Polyclay was developed in collaboration with one of polymer clay’s pioneer artists, Donna Kato. With other professional artists in mind, this formula embodies the most desirable working properties possible. An oven-hardening clay that cures strong and is non-toxic & sulfur-free. Features a smooth consistency that is not too sticky, yet is firm enough for details. Easily mix together to create any color imaginable! Highly-pigmented, pure colors formulated especially for color mixing. For permanent works of art that resist breaking and wear over time. Made in U.S.A.