Porous, lightweight. Combines the best features of rigid hard trays and soft liners. Bottom channels provide instant heating and cooling. Convenient and fast. Porcelain and molten metal will not stick to tray. Fire cases of any size and shape directly on it. No pins or pegs. Long service life – will not fracture in the furnace or during cooling. Thermal shock resistant. Light and easy to handle. Holes can be drilled into trays with a fine bur to create custom supports. Round trays conform to most modern furnace designs. Square trays fit square muffles and round muffles with 3-1/2" diameter, and allows the largest number of units to be fired simultaneously.

Rigid sponge ceramic evens the heat flow around the workpiece. Thermal shock resistant for longest service life of an rigid sagger tray. No pins or pegs required when used with Thermoz tray liners or Glazing Pads. Zero coefficient of expansion prevents cracking. Resists contamination and discoloring of porcelain. Square trays allow more individual units to be fired simultaneously, and are raised on parallel rails that facilitate quick cooling and even heat flow. Square trays fit most modern furnace designs and are supported by three ceramic legs to provide quick cooling and ease of handling. Round trays fit all standard round muffles. Square trays fit most round and square muffles.