Bookmarks have no fixed specifications and shapes, and can be made according to your own hobbies. In ancient times, bookmarks were used to do topics and write book names, all of which were posted in the upper left corner of the cover of ancient books. Bookmarks are generally small tools used to record the reading progress of a book. They are sandwiched in the book so that you can continue reading next time, so that you can make records and not lose them easily.