Fountain pen calligraphy is a very elegant and delicate way of writing, suitable for letters, signatures, calligraphy works and other occasions. If you want to practice pen calligraphy, here are some suitable copybook recommendations:

1. "Regular Script Fountain Pen Copybook": This copybook is based on regular script and is suitable for beginners to practice basic strokes and glyph structures. It contains commonly used Chinese characters and words, with detailed stroke order and demonstration illustrations for each character.

2. "Running Script Fountain Pen Copybook": If you have mastered the basic skills of regular script, you can try to practice running script. This copybook is based on running script and contains some commonly used idioms and famous sayings. The characteristics of running script are smooth strokes and fast writing speed.

3. "Cursive Pen Copybook": Cursive script is a style in the art of calligraphy, which is characterized by concise and coherent strokes. This copybook is based on cursive writing and contains some classic poems and famous sayings. Cursive writing requires certain skills and experience, and is suitable for practitioners with a certain foundation.

4. "Brush Copybook": Although this is a brush copybook, the glyph structure and stroke order are also very helpful for practicing pen calligraphy. The characteristics of calligraphy are rough and powerful lines. By practicing calligraphy, hand stability and stroke control can be improved.

No matter which copybook you choose, you need to practice every day for a period of time to gradually improve your writing skills. In addition, you can also refer to some calligraphy tutorials and videos to learn more techniques and methods. Remember, practicing pen calligraphy requires patience and perseverance, and progress can only be made through continuous practice.