2. Four-color machine-printed black. Dear friends say c30 can be added, but in fact, more can be added. But simply adding a color will make it glow from the side, which is somewhat inappropriate for the food industry. Our experience: c60m60y40k 100, this black color is very thick, especially after film covering.
3. Some people may say that I want to print black, which is simply C100m100y100k100. Isn't it darker? No way! ! ! It is impossible to print in this way. Because the adsorption capacity of paper to ink is at most 300, that is to say, the sum of the four values of cmyk cannot exceed 300! ! I mean a large area.
4. It is recommended to use high-quality paper when printing a large area of black, because good paper does not have so much paper ash when printing, otherwise it will be easy to get dirty. If the printer is careless, there will be a lot of dirty spots when printing.
5. When printing a large area of black, if you use anti-white characters, don't use too small fonts or some fonts with thin strokes, otherwise the printing will be blurred, especially if the width is large.
6. When printing a large area of black, if you use the reverse white line, don't be too thin, otherwise the printing will be blurred, especially when the width is large.
When using four-color printing process, in order to ensure the correct reduction of levels and colors, the ink layer thickness of each color should be strictly controlled. Generally, in four-color printing, the solid density of black does not exceed 1.8. Printing large black solids with this density will lack solid visual effect. The common forcing method is to overprint about 40% cyan on a large black area.
Black is overprinted with a small amount of cyan, which is still black in hue, but the visual effect will be stronger. It turned out that when only one color was printed on white paper, it was because of the paper wool in the printing process. The accumulation of paper powder on the blanket or the transfer of ink caused by other reasons will make white sand holes appear on the black field, and the contrast between black and white is very conspicuous. If it is overprinted by cyan flat screen, even if there are few sand holes on the black ground, the contrast between black and blue is less conspicuous than that between black and white, which can make the black background look more uniform and beautiful, because it is no longer a white paper base, but a cyan dot.