Offset printing
Lithography, also known as lithography or planar printing, is a traditional printing method mainly used to print flat or slightly raised patterns. The characteristic of this printing method is to use a flat lithography plate as the printing plate, and form the difference between the pattern and the non-pattern part through chemical or physical treatment, so as to realize printing.
Lithographic printing plates are made from flat stone slabs, the surface of which is usually sanded to give it a smooth, even surface. The part of the pattern that needs to be printed on the slate is processed on the surface by chemical or physical methods. The commonly used methods include: depositing ink or colloid on the surface of the slate to form a pattern, or forming depressions or raised pattern.
In the printing process, the lithography goes through three steps of inking, wetting and printing. First, ink is evenly coated on the surface of the lithographic plate, and then water or wetting liquid is evenly sprayed on the surface of the slate through the wetting system to keep the non-patterned part moist and the patterned part to leave ink. Finally, the lithographic pattern is partially printed onto paper or other printed material by a printing machine.
Lithography is an efficient, accurate and repeatable printing method widely used in industries such as publishing, printing and packaging. It can print various materials and colors, including paper, plastic, metal and ceramics, etc., and has a wide range of application prospects.
Toppan Printing
In letterpress printing, the layout is protruding due to the part of the pattern, so that the ink can only be printed on the pattern part, and then the printed pattern is transferred to the material by contacting the printing plate with paper or other printing materials. Therefore, letterpress printing is also known as letterpress printing or letterpress printing.
The printing pages of letterpress printing are usually made of wood blocks, typefaces or rubber plates, etc. These printing layouts all have a common feature: the pattern part is convex, and the non-pattern part is concave. In the printing process, ink is applied to the printing plate, and then the ink is transferred to the printed material by pressure.
The main advantage of letterpress printing is that it prints sharply and clearly because the ink is only printed on the patterned part. In addition, letterpress printing also has the advantages of low cost and easy operation, and is widely used in packaging, greeting cards, envelopes, advertisements, tickets, etc.
However, letterpress printing also has some limitations. For example, because the printing layout is convex, only shallow patterns can be printed, and the printing effect cannot be compared with other printing methods. In addition, the layout of letterpress printing is more difficult, requiring a high level of skill and professional equipment.
Flexographic printing
Flexographic printing is characterized by the use of flexographic printing plates and liquid inks to achieve printing. Flexographic printing plates are made of rubber or plastic that can bend and stretch, so a variety of materials with irregular surfaces can be printed. Flexographic printing is widely used in packaging, labels, stickers, tissues, newspapers and other fields.
The printing plate of flexographic printing is usually made of a flexographic printing plate coated with photosensitive material. In the printing process, the printing plate is placed on the printing machine, and the ink is evenly coated on the printing plate by the coating system. The printing plate is then brought into contact with the printed material by pressure, causing the ink to be transferred to the material. During the transfer of ink, the printing plate bends and stretches, allowing materials with curved or irregular surfaces to be printed.
Flexographic printing has the following advantages: fast printing speed, high printing quality, can print various types of materials, suitable for mass production, etc. In addition, flexographic printing can also use a variety of ink types, such as water-based inks, solvent-based inks and UV-curable inks, etc., to meet different printing needs.
However, flexographic printing also has some disadvantages, such as high production cost of printing plates, poor wear resistance of printing plates, etc. In addition, flexographic printing may generate harmful VOCs and waste water, and measures need to be taken to control environmental pollution.
gravure printing
Gravure printing uses a gravure plate to make a printing plate, then scrapes the ink off the raised surface so that the ink stays only in the grooves, and finally brings the printing plate into contact with the printed material to transfer the ink to the surface of the material.
Gravure printing is a high-quality, high-volume printing method, usually used to print high-quality magazines, books, picture albums, packaging boxes, etc. Gravure printing plates are usually made of metal, and the surface is chemically etched or mechanically engraved to form the printed image, which includes many small grooves.
Gravure printing has the following advantages: high printing quality, fast printing speed, suitable for mass production, can use a variety of ink types, etc. Gravure printing can also use a high-tech electronic wire control system to make the printing process more accurate and efficient.
However, gravure printing also has some disadvantages, such as the high cost of printing plate production, the groove depth and shape of the printing plate have a great impact on the printing quality, and it is not suitable for printing large areas of solid colors, etc. In addition, gravure printing generates environmental problems such as waste water and harmful gas emissions, and measures need to be taken to control pollution.
