Which of the following does not belong to the basic elements of calligraphy?

The basic elements of calligraphy include: 1, stroke structure: one of the basic elements of calligraphy, which refers to the shape, size, direction and weight of strokes.

2. Glyph structure: The second basic element of calligraphy refers to the combination and arrangement of glyphs.

3. Layout: The third basic element of calligraphy refers to the overall layout and typesetting of works.

4. Pen and ink color: one of the basic elements of calligraphy, but not one of the basic elements, refers to the color effect expressed by pen and ink.