Printing is a process of copying an image or text onto paper or other materials, either by machine or by hand. Printing technology has always been one of the important means for human beings to spread ideas, culture and information. It can be traced back to ancient Chinese woodblock printing and European type printing. Modern printing technology includes a variety of technologies, such as flat printing, letterpress printing, gravure printing, flexographic printing and digital printing. Printing can be used in books, newspapers, magazines, advertisements, packaging, greeting cards and other fields, and occupies a very important position in modern society.