There are many types of printing presses, which can be categorized according to the following five aspects: according to the layout type is divided into: letterpress printing press, lithographic printing press, gravure printing press, hole version of the printing press. According to the size of the paper specifications are divided into: lithographic paper or sheet-fed printing machine, web printing machine; in accordance with the number of printing colors are divided into: single-color printing machine, two-color printing machine, multi-color printing machine; in accordance with the printing format is divided into "octavo printing machine, quarto printing machine, folio printing machine, full-sheet printing machine, ultra full-sheet printing machine, etc.; although the classification of many ways of the printing machine, however, the printing machine The core part of the printing device is the imprinting mechanism, therefore, based on the way the pressure is applied, the general printing machine is divided into flat press flat type, round press flat type, round press round type, oblique press flat type.