An offset printing press is a type of lithographic printing press . During printing, the printed images and text are first printed from the printing plate onto the rubber cylinder, and then transferred to the paper by the rubber cylinder.     Offset printing machines can be divided into sheet-fed offset printing machines and web-fed offset printing machines according to different paper feeding methods; according to the number of printing colors completed in one paper pass, they can be divided into single-color, two-color, four-color and multi-color printing machines; according to the printing substrate The maximum paper format can be divided into small offset printing presses , six-open, four-open, half-open and full-sheet printing presses.   In addition, there are double-sided printing presses that can complete two-sided printing at the same time in one paper pass. Sheet-fed offset printing press is a lithographic printing press , used for printing high-grade commercia...