hello! Plastilina never gets hard---if you heat it , it will melt. Its used for
design work and animation. The polymer clays like Sculpey, Sculpeylll, Fimo,
Premo, Modello, Kato Polyclay and Cernit all harden in an oven at less than 300
degrees F. Thes clays range in hardness after baking and cost---here in the
US, Sculpey is the least expensive and also the least firm, and the most
brittle after baking. Different clays are good for different uses, artists have
their favorites. Look it up in the archives at www.polymerclaycentral.com or
www.glassattic.com for more information
Sarajane

Sarajane's Polymer Clay Gallery
http://www.polyclay.com