I have sent you some boxes samples. These boxes are made of 120-140g paper, thickness around 0.6cm [ 是0.6mm 吧？？]. This thickness is best for the seed to sprout. But boxes with this paper thickness are a bit soft. The factory told me that if the paper is thicker, the sprout successful rate may decrease. Because we do not have thicker paper at the moment, we use this existing normal paper to make samples for your reference.