Black is a color with many different cultural meanings, and black has never been out of date. But black printing is the most problematic color in book printing China. For example, the color on the screen is very saturated. But after printing it, there is a little gray in the black. Or the color is not saturated, or the text in the full-page black is printed with ghosting.
The printing black value can be divided into four-color black and single-color black. The corresponding printed four-color black black value cmyk is: C100, M100, Y100, K100. The monochrome black CMYK is: C:0, M:0, Y:0, K:100.
1. Four-color black in book printing
The black after CMYK four-color superposition is generally used for large-area printing. And is not suitable for text printing. Many large-area black monitors look very black, but the printing is not enough. That is because the designer uses a single black when designing black, the color value: C0, M0, Y0, K100. So this problem will occur.
We recommended that the full-page large area is black. And the four-color black value should not exceed 250 (C+M+Y+K color value). If the color value is greater than 250 in book printing, the paper may not hold the ink, and it is easy to be dirty. If there is text in it, it will be printed out, which will affect the printing effect. This color is not recommended when book printing in China.
We recommend to set the black color value: C30-40 (blue) M0, Y0, K100. Single color adds 30 blue, and it will be faintly blue in the sun when book printed, and the color looks darker. This black is recommended for large-area book printing.
The book printing time for large area black is best to use a four-color machine. The color is saturated and uniform. The monochrome machine prints black color is not saturated or not uniform. That’s why we recommended that customers with high color requirements use four-color printing in book printing China.
2. Monochrome black in book printing
Only K color value is 100, C, M, Y is 0, generally used for text, not suitable for large-area printing. The large-area printing is best to use a four-color machine to print, build color value C30-40 (blue) M0, Y0, K100, the printed color saturation. Or black (spot color) printed on 2 sides. Specific according to customer or document requirements.
3. Notes for black in book printing
Use high-quality paper when printing a large area of black. After printing, oil or film, gloss film or sub-film. The paper is not easy to stick to the plate, varnish or matt oil can protect the printing surface. And the film can protect the printing surface.
If there are exposed white or white lines during the printing of a large area of black. The font should not be too small, the strokes should not be too thin, and the lines should not be too thin. It is responsible for the blur of the printing, especially for the folio printing machine. Do not use four-color black for four-color values.
In the large-area printing black, there are thin white characters or thin lines. You can stroke the text, the stroke size is 0.3-0.5mm, and the color deviation will not exceed this range.
The black gradient cannot only be black to another color gradient. Otherwise it will not look good in the middle. For example, from black to red, the gradient from K100 to M100 Y100 cannot be changed. It should be C0, M100, Y100, K100 to M100, Y100.