FOUR BLOCKS Sculpey iii 3 lll Polymer Oven Bake Clay 111 Each block weighs 56g and measures 60mm x 45mm x 20mm. Polymer Clay is a highly versatile modelling material that is hardened by baking in your home oven. It stays soft until baked. Once baked it is permanent and can be cut, sawn, glued, painted or added to and re-baked. More information in Full description.