The font written with pen has the characteristics of clear strokes and smooth lines. Pen characters are usually used for writing on formal occasions, such as official documents and letters. Characters written in chalk are characterized by rough lines and different thicknesses. Chalk characters are often used in teaching, speaking and doodling on the blackboard. The characters written with brush are characterized by rich pen and ink and changeable strokes. Brush calligraphy is often used in calligraphy practice and artistic creation.