If the calligraphy is beautiful, you can use the following expressions:
1. "Your calligraphy is so beautiful."
2. "Your calligraphy is really unique and artistic."
3. "Your handwriting is clear and neat, and it looks very comfortable."
4. "Your calligraphy skills are really superb, and every stroke is so powerful."
5. "Your calligraphy is so graceful and charming."