What font should be used for gift seals? Is it yin or yang?

Famous seals are generally divided into two types: Zhu Wen (Yang Wen) and Bai Wen (Yin Wen). If you are a thirty-year-old literary and art worker with a relatively high taste, I suggest you use Yang Wen.

As for the font, if the friend you are gifting is good at calligraphy and painting, he should use a seal in seal script instead of a seal in official script or regular script, otherwise it will be out of place and directly affect the artistic effect of the calligraphy work. The art of appreciating seal cutting with literary meaning complements poetry, calligraphy and painting.