Liu Bin sketch ruler is a kind of sketch ruler, which is 22 cm long and 3.3 cm wide. Suitable for octo paper, mainly used for drawing head portraits.

Liu Bin sketch ruler only needs to draw the position of the top of the head on the portrait. Through the position of the top of the head, put the special ruler for sketch portrait vertically on the sketch paper, mark the scaled name and place on the special ruler for sketch portrait, draw these marks horizontally with a pencil, and then determine the head position through the intersection of the horizontal line and the vertical line, so as to draw the portrait of millimeter level very accurately and quickly.