Because, it doesn't crack easily and be slippery by coating the surface, masterpiece of Katayama to whom productivity is steady.

The quality is steady by a hard plastic material. It doesn't crack easily and be slippery by coating the surface, it leads to better productivity. The width of the ditch can be freely set. Moreover, the thickness is prepared from 0.3mm for thin paper to 1.2mm for cardboard at intervals of 0.1mm.