羊毛毡厚度为1.2 ±0.25 mm (0.05 ±0.01 in)，羊毛含量不超过30%，其余成分为人造丝。
规格：
材质：30%羊毛, 70%人造丝。
尺寸: 9 inches (22.9cm) 宽 x 12 inches (30.5cm) 长x约3/64 inch-1/16 inch (1-1.6mm) 厚。


UL2556 clause7.19  Durability of ink printing
 A kraft felt with a thickness of 1.2 ±0.25 mm (0.05 ±0.01 in) not having more than 30% wool content and the remainder of the composition being rayon.
Specification：
Material: 30% wool, 70% rayon.
Dimensions: 9 inches (22.9cm) wide x 12 inches (30.5cm) long x approximately 3/64 inch-1/16 inch (1-1.6mm) thick.