(1) The color of the board is the natural color of the resin.
(2) The texture should be uniform and the appearance should be flat. Cracks, bubbles, delamination, mechanical damage, knife marks and other defects are not allowed.
(3) Allowing slight cloudiness to be tight.
(4) It is allowed to have no more than one non-metallic impurity having a diameter of 0.1-0.5 mm and a non-metallic impurity having a diameter of 0.5-2 mm on an area of 10 × 10 cm.
(5) The density is 2.1-2.3T/m3.