
There are two basic kinds of sculpting clay, Water Based Clay and Oil Based Clay.
Check out our Oil Based Clay
Water Based Clay
Water based clay is simply that, clay mixed with water. It is usually very inexpensive but must be kept covered or it will dry out. Water based clay is easy to work when it has just the right amount of water, which is easy to manipulate. It is easy to remove from a mold with a water sprayer. Its disadvantages are equal to its advantages; it is often hard to control especially if a project goes into many days, it sags and separates easy, and it can't be used with plastics, epoxies or polymers.
Crayola White Air Dry Clay

Crayola Air-Dry Clay is a fine, natural white earth clay that air-dries to a hard solid. No kiln or oven necessary! Easy to use with traditional modeling techniques, it's also a snap to clean up.
Smoother, finer and less sticky than traditional clay; needs no oven or kiln.
Softens easily with water and quickly cleans from hands and surfaces.
Use with traditional techniques such as pinch, coil, slab, and score-and-weld; make stamped impressions or beads; embed found objects.
Can be painted with tempera, acrylic or watercolors when dry.
Resists cracking.
Convenient reusable plastic bucket helps keep clay fresh.
Also available in a 25 lb. Value Pack.
Mexican Pottery Clay

Mexican Pottery Clay will shrink during drying, so it is best to hollow out bulky sculptures or wrap a slab of clay around a loose crumpled paper armature before modeling.
Allow the finished piece to dry slowly and evenly on all sides at room temperature and away from heat until hard. When piece is completely dry, decorate with AMACO Rub 'n Buff, school paints, temperas, acrylics or liquid crayons. After decorating, it is a good idea to coat with shellac or varnish to seal it and make it water resistant.
AMACO Magic Mud

This non-toxic, non-staining, air dry natural clay is fun to use and it's reusable! Developed by a classroom teacher, Magic Mud promotes endless learning, encourages unlimited discovery, increases sensory motor development, and allows self-expression. Air-dried objects made with Magic Mud can be turned back into mud again by breaking into smaller pieces and adding water! Magic Mud can also be fired in a kiln.