The simplest form of model making or sculpting is with clay. Working with this flexible and malleable material is both interesting and enjoyable. It is quite easy to create even three dimensional figures with clay. So much so that, even small kids can easily use their creativity to knead, squash, roll and otherwise shape the material into any form they wish.
The versatility of the humble clay is such that it suits children, novice artists as well as seasoned sculptors. In fact, sculptors often create large figures with clay. However, as the clay cannot support its own weight, an internal metal armature is used to build the model.
Clay comes in a ready to use form and lends itself beautifully for making masks, prototype models and special effects as well. In fact, clay modeling is also used in animation and this dedicated art is known as claymation.
Types of clay
Not only can clay can be molded in a number of ways, it comes in a variety of types too. They vary depending on the composition and process of production as well. While water-based clay generally tends to harden on exposure to air, non-hardening variations are also available. In fact, some clay types need to be heated in an oven for the model to harden properly. This is generally used in ceramics.
The non-hardening clay is either oil or wax based that keeps it from drying out, cracking or shrinking. This is preferred by artists and sculptors as it stays flexible, holds fine details well and can even be reused by heating. There are certain high grade clays that stay permanently malleable and so can be used time after time. Then there is ballistic clay that replicates animal tissue and is useful for testing body armor and in forensics.
The final choice of clay is personal and is based as much on the feel, texture and hardness of the material, as on the potential requirements of the finished piece.
And irrespective of the choice of clay, you will surely need diverse tools to cut, pierce and sculpt the clay before you can form it into the shape you want. Cutter, trimmer, rasp and tongs are but just a few of them. And once the clay modeling is ready, it is finished with paint or even stain effects can be created.
Special care is needed when clay molds are used for making resin, rubber or metal casts. The mold has to be sealed properly prior to casting as the clay can distort or even dissolve when it comes in contact with the solvent. Furthermore, the sulfur content of certain clays often ends up inhibiting the setting of silicone rubbers and polyurethane rubbers. Therefore, sulfur free clay is considered a better option for clay modeling.