The press plate solves the problem of warping or curling of the piece when removed from the kiln. Immediately after you take your piece out of the kiln use the plate to press the piece flat. It is recommened the surface underneath is metal or burn resistance. Some cracking may occur so multiple firings may be needed.
This is the smaller model, great for small pieces and tiles. The press plate is made from low carbon steel with and aluminum handle. The steel measures 1/2" thick and 8X8 inch square weighing approximately 9 pounds.
 "Small Press Plate")