There has been a long history of the idea and application of reproduction of texts or images. The so-called reproduction, in printing, is the process of replicating the texts or images repeatedly by using ink or other coloring agents to reveal the details that are engraved or etched on the same text or image model. For this reason, characters on the model must be in reverse form before they can be reproduced and then displayed in upright type format. Long before the advent of woodblock printing, there existed various classical reproduction techniques in China, such as affixing seals, creating rubbings from tablet inscriptions, etc., which inspired the reproduction of books by woodblock printing.