Sulphur-free clay, available in soft, medium and hard.
All three can be melted and poured.
Small pieces of any of these clays can be further softened in a microwave oven to make them more pliable. This should not be done for more than 15-seconds at a time. Use caution once clay has been removed from the microwave. It will be much hotter and more liquid in the center, and if squeezed it could squirt dangerously hot liquid clay from the inside.
Available in 5-lb. units or 10-lb. units.
$5.75 per pound.