In the printing process, a continuous tone picture image in the original is converted in a half tone image on the printed material by using screen dots printing technique.
印刷工艺过程中，原件上的连续调画面是通过网点印刷技术转换成印刷制品上的半色调影像的。
2
Wash drawing: a drawing made by a brush in washes with a single pigment of black or dark colour soluble in water, to be reproduced by the half-toneprocess.