Printing process
Common printing processes are: offset printing, silk screen printing, gravure printing, embossing (watermarking, flexo printing), hot stamping and special printing.
In order to give you an intuitive idea, let's list all kinds of process-related products
1. Offset printing - cards, books, albums, packaging cartons.
2. Silk screen printing - T-shirts, leather, fabrics, cultural shirts.
3. Gravure - instant noodle bags, melon seeds, snack bags.
4. Embossing - cartons, KFC lunch boxes, milk cartons, etc.
In addition, there is a hot stamping process, which is actually a composite of offset printing and silk screen printing to make a transfer plate, and then hot stamping onto the substrate.
In addition, there are also digital printing, flatbed direct injection and other process types, which belong to special printing.
1. Offset printing
Offset printing is a kind of lithographic printing process, which is based on the principle that oil and water are not miscible, and you can go to my "Prepress Technology" course for specific details.
The ink passes through the plate, is transferred to the blanket, and then to the substrate. Therefore, the ink is very thin and uniform, the effect of overprinting is very real, and offset printing is also the best process for color reproduction.
The production of offset printing plate can use FTP and CTP two processes, FTP is to output the film plate first, and CTP is to directly expose the plate, each with its own advantages and disadvantages.
2. Silk screen printing
Silk screen printing is a process of missing printing, and the printing plate is a stencil. The ink leaks to the substrate through the mesh, so the ink of the screen printing process is thicker, and this thickness can also be adjusted by the thickness of the mesh, and its color overprinting effect is poor, and it is generally a spot color printing and color block overprinting.
The production of silk screen printing plate is mainly in the FTP method, that is, the film is output first, and then the plate is exposed, but the silk screen film and offset film are opposite, under normal circumstances, the silk screen is printed out of the positive film, and the offset is printed out of the reverse film.
3. Gravure printing
Gravure printing is a gravure process, mainly printing on plastic films, the ink used is UV ink, UV ink is not unique to gravure, and now many offset printing also use UV ink. For example, the printing on some film sheets belongs to the three-dimensional printing process, and the printing on the grating sheet also uses UV ink.
At present, gravure plate-making technology adopts CTP plate-making, which is the so-called electric engraving mechanism plate in the industry.
4. Embossing (watermark or flexo)
Of course, with the development of modern science and technology, movable type printing has become a kind of history, and the embossing in the modern sense adopts resin plate technology.
This kind of printing plate, after being exposed, the illuminated part is cured, and the unlit part can be rinsed off with water, so as to obtain a letterpress. A modern process called watermarking or flexographic printing.
Fifth, hot stamping
Hot stamping belongs to a kind of heat transfer printing process, and the production of hot stamping paper can use different processes such as gravure printing, offset printing, silk screen printing or digital printing.
6. Special printing
Generally, it refers to the process of direct digital printers, such as flatbed UV universal printers, digital printing machines and so on.