Signing is not taught in any school or university. What characteristics should a signature have? For example, it is not like the art of calligraphy that has a series of special teaching points that can be learned. What I am working on is using letters and playing with the shape of letters. I usually use a simple line that is not difficult for the person who wants the signature. It's kind of like designing the decoration of a house and taste should be used so that everything fits together in the best way.