Tracing red belongs to the practice method of soft pen calligraphy. Tracing red is usually used in the practice of brush calligraphy. It refers to drawing the fonts on the copybook on red paper, and then adding strokes to it to practice writing skills.
For the practice of hard pen calligraphy, such as pen writing or pencil writing, tracing red may not be applicable. Because the strokes of hard pen calligraphy are usually regular, tracing red may have an impact on the shape of strokes, which is not conducive to the practice of hard pen calligraphy.