Plasticine is the name brand of a modeling clay with a putty-like texture. It looks, works, and feels similar to traditional clay, but does not dry out or harden and cannot be fired. It was invented for student use around 1887 by William Harbutt, then the headmaster of the Bath School of Art and Design in England. Although you may not be familiar with the Plasticine brand name, you have very likely encountered this product in your life already! Generic versions are readily available for children’s crafts in a wide range of colors. Because of its malleability, Plasticine is also used in the production of claymation stop-motion videos. The award-winning Wallace and Gromit short films used plasticine models.
Plasticine modeling is a method used by artists to create cast sculpture in various shapes. It is more advanced than simple scratch tiles and involves the creation of a raised clay model on a flat surface. This model is then used to make a sand mold which allows for the casting of a metal replica, complete with fine detail.
Method of Use
Unlike scratch tiles, clay models aren’t confined to a rectangular shape. In further comparison, a finished scratch tile becomes a mold in and of itself, while a clay model is a structure from which a mold will be created.
It is necessary to construct a sturdy base for the model. The first step involves cutting out the model’s basic form from foam core, similar to a silhouette. The foam board is then securely attached to a thin wooden platform for stability. Since Plasticine does not require firing, no special materials are needed. An appropriately sized cut of plywood and foam board bought from a craft store will get the job done.
After the construction of the base, modeling clay is then directly applied to and built upon the foam core silhouette. The foam cut-out serves to guide the artist in keeping the proper shape and proportions and the wooden backing allows for the entire model to be easily manipulated and transported.
Once the model is finished, a mold of it must be created. This is done using a high sided frame called a flask and a sand/resin mixture. The model is placed inside the flask and packed with sand. Once packing is complete, the clay model is removed leaving behind its hollow imprint. After ensuring there is no remaining Plasticine left in the sand, the hollow mold is then ready to accept molten metal. After cooling, the mold is removed and a replica of the clay model is obtained. The sculpture is then ground and finished to bring out shine and detail.