Hollow characters express the traditional calligraphy art in a unique outline form. In traditional calligraphy, we should not only accurately master the rules of single stroke, but also be familiar with the frame structure and the techniques of line drawing.

The method is as follows:

1, each font is composed of strokes. In order to reflect the three-dimensional sense, the strokes are first written as hollow closed shapes (mostly rectangles). Simple horizontal and vertical strokes are best written, and crossed strokes are also written in closed shapes (lines cannot cross). This step can be omitted after proficiency.

2. Then imagine that the light is projected from the upper left corner, and all the lines (blue parts) that can be illuminated by the light are removed. Obviously, the horizontal line above and the vertical line on the left must be removed.

3. That is to say, the last remaining lines are the lower horizontal line, the right vertical line and the angle of < 0.