Educational Colours Modelling Clay is a traditional modelling clay and ideal for classroom, home and stdio use. Easy to use, and available in many colours. It is non-toxic and safe to use for children and adults. Made from a quality mineral base, this world famous modelling compound doesnt harden and can be re-used again and again Not to be used in kiln or oven. Shape your creativity with EC Modelling Clay! 500 gram block in the colour black.