The definition of gravure printing refers to the following graphic way of printing, gravure printing and relief printing offset is different, relief printing and dot density to represent the level of the image, and gravure printing depends on the depth of the net hole or the size of the open area to represent the level of the image.
Mesh is the storage pit of gravure printing ink. The opening and depth of gravure printing pit should be changed according to the amount of ink. The bigger the hole volume of gravure printing part is, the more the amount of ink is, and the thicker the ink layer on the printing product is. The mesh size of the printing part is smaller and the ink is less, so the transfer to the ink layer is thinner. The thicker part of the ink layer is that the image is darker, the ink layer is thinner and brighter. Because the gravure ink layer is generally thicker, the printing image generally has a slight protrusion.
In relief and tablet, the network line is invisible. When the area ratio of grid points in adjacent grids reaches 100%, these points will be connected together. However, gravure is also different, although the grid line is invisible, but there is actually a wall.
The screen wall is used to separate holes and support the gravure scraper base. The role of screen wall in gravure printing is mainly embodied in two aspects: one is to support the scraper of gravure printing press to prevent it from scratching in the hole; the other is to prevent ink from flowing through the hole, because of the existence of the screen wall, there is usually no dot area of 100% in gravure printing.
The holes on gravure plate have three variable degrees of freedom; the depth of mesh concave, the area of mesh opening and the shape of mesh opening. In making gravure plate, the three degrees of freedom of mesh can be changed to change the storage of ink, so as to reproduce the changes of text and text depth.
Gravure plates usually have four types of gravure screen plates:
In the same open area, this is a typical intaglio dot, usually referred to as "classical intaglio" or "traditional intaglio". This net hole represents the change of order by changing the horizontal depth of the net hole. The net depth of the net hole, the color of the depth image and the shallow area of the net hole where the color is light, are constant because the net area of the hole is constant. The net area of the hole is the same, so the wall thickness is the same.
2. The concave depth of net hole is unchanged and the open area is changed. By changing the image represented by the open area of net hole, the net hole area is large, the area of dark and light color holes is small, and the concave depth of net hole is unchanged. The characteristics of such grid points are similar to the principled offset joint represented by pictures, so this gravure plate is also called "dot gravure printing". "
At present, this kind of cave is the most common type of cave. The characteristics of the cave are: in the dark color, the opening area and depth of the cave are larger; in the light color, the opening area and the depth of the cave are very small.
4 FM frequency modulation principle application point screening gravure printing, gravure printing can generate frequency modulation caves and grid points. The characteristics of gravure printing are: the spatial position changes randomly at gravure Internet points, but the net area of the hole is the same. In order to be in the dark area of the image, the "frequency modulation cave space" should be controlled reasonably, not completely with the developed areas without walls. Machine, the above four types of grid points, can be made by electronic engraving and laser engraving.