Clay is a material that is often first introduced to children. It lets them discover a new material that flexes and forms in any way they desire. Among adults, clay is used by artists, sculptors and animators for creative purposes. Both polymer clay and modeling clay have their uses in arts and crafts, but they perform very differently. The project should determine whether polymer clay or modeling clay is the better material to use.
Material and Color
Modeling clay is an oil-based compound, while polymer clay is polyvinyl chloride, a plastic-based material. Both materials are available in a wide range of colors, but polymer clay has more options in faux colors, such as granite or translucent shades. Modeling clay has only shades of color while polymer clay has colors that glitter.
Modeling clay is available in air-dry or no-dry options. Modeling clay is created so that it can be used over and over again so that it never dries out. Polymer clay hardens when it is baked in an oven, though in its unbaked form, it does have a tendency to crumble if left out too long or if it gets too old. There is a special additive sold at craft supply stores, called clay softener, for hardened clay. A few drops of the additive will soften the clay again. Modeling clay stays flexible and pliable.
Animators often use modeling clay because it is reusable. Modeling clay characters are easily moved and rearranged without the worry of breaking their creation. Sculptors use it to visualize ideas while artists use it as a sketching aid. Polymer clay is mainly used for finished projects. Jewelry makers use it for making unique beads in necklaces and earrings, and doll makers apply it to create fairies and figurines.
Because modeling clay is mostly used in non-drying applications, polymer clay is a more durable material for finished projects. It is waterproof when hardened, making it a fitting material to use for buttons, fish tank accents or jewelry. It is also paintable, whereas non-drying modeling clay is not. Air-dry modeling clay is available but is primarily used for children's crafting, so it is not as durable as polymer clay. There are also different types of polymer clay, each one designed for a special use. Read the manufacturer's suggestions about what type to use for your project.