It is engraved across the full face with minute cell at 60 to 120 lines per cm and to a specified depth, usually 50 micron to 100 micron to provide a better ink distribution.

• 它的整个表面刻上有一定深度的微细窝；密度由每厘米60至120线，深度通常为50至100微米。这样，油墨分布得更为平均。