type of printing
Classification of printing methods based on the relative position of graphic and non-graphical areas on the plate

(1) Letterpress printing, the graphic part of the printing plate is raised, which is obviously higher than the blank part. The printing principle is similar to the seal. The early woodblock printing, movable type printing and later type printing are all letterpress printing.

(2) Gravure printing, the graphic part of the printing plate is lower than the blank part, and is often used for printing banknotes, stamps and other valuable securities.

(3) Lithographic printing, the graphic part and the blank part of the printing plate are almost on the same plane, and the printing method is carried out using the principle of oil and water incompatibility.

(4) Stencil printing, the graphic part of the printing plate is a hole, and the ink is transferred to the surface of the substrate through the hole. Common stencil printing includes hollow plate and screen plate.

Classification of printing methods according to the feeding method of the printing press

Flat paper printing: Also known as sheet-fed printing. It is printed on flat paper.

Web printing: also known as web printing. It is a method of printing using web paper.

Classification of printing methods according to whether or not the plate is in contact with the substrate

Direct printing: The ink on the printing plate is printed in direct contact with the substrate. Such as letterpress printing, gravure printing, screen printing.

Indirect printing: The printing method in which the ink of the printing plate is transferred to the substrate through the blanket.

Classification of printing methods according to whether the printing plate is used or not

Plate printing: The printing plate is printed on the substrate using a pre-made printing plate. Such as letterpress printing, gravure printing, screen printing.

Freeprint: A method in which a printing plate is printed directly on a substrate through a computer-driven printhead (or printhead). such as digital printing.

Classification of printing methods according to printing principles

1. Physical printing, the printing ink is completely a kind of accumulation load in the printing part, the non-printing part is concave or convex, and the height of the printing part is different and cannot be stained with the printing ink. Part of the printing ink is transferred to the material to be printed, which is only a physical and mechanical action. Generally, letterpress printing, gravure printing, stencil printing, dry lithography, etc. are all physical printing (the printing surface is higher or lower than the non-printing surface).

2. Chemical printing, the non-printed part of the printing plate (non-printing surface) does not stick to the printing ink, not because of this part is concave, convex, or blocked, but because of chemical action, it produces water absorption and ink repellency The film dictates. Of course, the printed part (printing surface) absorbs ink and repels water, the non-printed part absorbs water and repels ink, and the water and grease reverse each other, which is still a physical phenomenon, but during the printing process, the non-printed part must be continuously supplemented with water-absorbing and repelling. A thin film of ink, so it is chemical printing. Offset printing falls into this category. In offset printing, glue substances should be added to the water tank solution to supply the mucus layer of carboxyl groups continuously, so as to keep the non-printing surface of the printing plate from being infected by grease.