When completely dry finished pieces are durable but not waterproof. Knead Mexican Pottery ClayTM to increase plasticity before modeling. Keep unused clay in a plastic bag or wrapped in damp cloth to prevent drying out. When completely dry finished pieces are durable but not waterproof. Knead Mexican Pottery ClayTM to increase plasticity before modeling. Keep unused clay in a plastic bag or wrapped in damp cloth to prevent drying out. It 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.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.