What material is good for calligraphy frame?

A calligraphy character frame consists of a frame and a rubber net. When in use, squares, horizontal rectangles, vertical rectangles and vertical lines of various sizes can be quickly drawn on the writing material by using the elasticity of the rubber net. It is convenient for calligraphy lovers to create and practice various calligraphy styles such as regular script, official script, seal script, running script and cursive script. At the same time, it can keep the writing paper flat, which has the advantage of prompting the writer to use a pen and hang his elbow in the center.