Encyclopedia of typesetting specifications and dimensions of ancient books

For example, what you need to do is 25*25cm, which is the size of the binding product. Your typesetting should be arranged according to the expanded size, 50*50cm, and then draw a reference line in the middle of 50*50cm and 25*25cm on one side, so that the content will be arranged in half without bleeding. You should leave a space of 1cm around the top and bottom, and there should be no text.