Heat conductive rubber pads are used to provide even heat to surfaces that might not be perfectly flat, and is our recommendation for imaging porcelain, stone and glass tile, glass cutting boards, and ornaments. Green silicon rubber pads are most commonly used in pressing to porcelain and glass. The 1/16" thickness is recommended for jewelry and porcelain ornaments. 1/8" is perfect for glass cutting boards, tiles and plaques. The red rubber is a stretchy material that can be used to rehabilitate a dye wrap or create a cusom wrap for an odd shaped item.