Gray Balance And Bottom Color Remove In Book Printing
The means to achieve neutral gray through three primary color overprint is called gray balance. Specifically, under certain printing conditions, the yellow, magenta and cyan primary color plates are combined and overprinted from light to deep according to a certain dot ratio to obtain achromatic (white, light gray, gray, dark gray and black) with different lightness. This whole process is called gray balance of book printing. Its meaning is to indirectly control all tones on the whole picture by controlling the gray part of the picture. It is a yardstick to measure the correctness of color separation plate making and color printing. It is the principle to be observed and implemented by all processes in the whole process of reproduction.
Factors affecting gray balance during printing include:
(1) The raw materials used in printing mainly refer to ink, paper, etc
(2) Printing conditions, including machine accuracy, printing pressure, wetting liquid, etc
(3) Printing color sequence;
(4) Ink layer thickness;
(5) Ambient temperature and humidity.
Bottom color removal is a process of reducing the proportion of three primary colors and increasing the proportion of black when using three primary colors to restore gray and black in four-color reproduction. Its purpose in book printing is as follows:
(1) Improve printability and ink dryness;
(2) Reduce ink cost
(3) Compensate the color deviation of the dark part;
(4) Keep the gray (neutral gray) printing reproduction stable.
Because the bottom color removal is the use of non-color structure technology in color printing reproduction, the black plate in four-color printing is particularly important.
Points to pay attention to when removing the background color
(1)The background color removal generally works in the midtones, dark neutral gray and near-neutral gray areas.
(2)Accurately grasp the control of the removal amount.
(3)Master the control of the removal point, that is, the range of removal control.