Why is it necessary to screen the images before printing the brochure?

Because the printing process determines that printing can only use dots to reproduce the continuous layering of the original manuscript. If you zoom in, you will find that it is composed of countless dots of different sizes. We see that although the sizes of the dots are different, they all occupy the same spatial position. This is because once the original image is screened, it is divided into countless regularly arranged dots, that is, the continuous tone image information is transformed into discrete dot image information. The larger the network, the darker the colors displayed and the darker the layers; The smaller the branch, the lighter the color it represents, and the brighter the level it represents. The fixed spatial position size occupied by each branch is determined by the number of grid lines. For example, if the number of grid lines is 150 lpi, there will be 150 branches in one inch of length or width. The position and size of the dot space are two different concepts. For example, C50% represents that the dot size occupies 50% of the dot space position, 100% refers to the dot size covering the entire dot space position, which is called "solid" in printing, and 0% means that there are no dots, only dot space position, so there is no ink printed on this area. Obviously, the larger the number of online listings, the smaller the space occupied by the branches, and the more levels and details can be described. In fact, the layers and colors of the original manuscript are reproduced through this method of hanging on the internet. album printing