1. strokes: strokes of calligraphy fonts have their own characteristics, which can be identified by observing the shape, size and thickness of strokes.
2. Structure: The structure of calligraphy fonts also has its own characteristics, which can be identified by observing the balance, symmetry and center of gravity of fonts.
3. Style: Different calligraphers have different styles, which can be identified by observing the style characteristics of their works.