Casting objects made of oil clay, wood, stone, and glazed ceramics typically don’t need to be sealed. But casting objects made of plaster, concrete, water-based clay, and copper should be sealed with a material-appropriate sealant. Always make sure your casting object is free of oil and dirt before you apply liquid latex.
When you’re applying liquid latex, brush the solution onto your piece from top to bottom. Brush the liquid latex 2 inches out from the base and let it dry before you apply another coat. After each coat, brush a coat on a spare piece of cardboard—you can use this one to gauge whether the latex has fully dried.