On the issue of calligraphy seal …

The handwritten seal for calligraphy and painting can be one word, two words, three words, four words or more, and there is no limit. You don't need to write someone's signature. Since it was painted with a seal, it means your autograph. You can be "someone's seal", someone's private seal, someone's seal, the city where you live, or a single surname, because you will definitely mention yourself.