Under color removal and use of three primary colors and black plates

Under color removal is proposed and implemented for modern color reproduction techniques. Began to use for photolithography, according to its principle using mask technology to operate by experience. In the 1970s, PCR (Programmed Color Reduction) was used in the specification of the German Haier electronic color separation machine. Translated into a programmatic color removal; in the Dainippon Screen Electronic Separation Machine Manual, ICR (Integrated Color Removal) was used to translate to full color removal; in the U.S. material, GCR (Grey Component Replacement) was used to replace gray components. Specialized circuits or related software implementations.

The actual application is difficult to distinguish, and the operation is also more flexible. After many years of application, the technology is mature. The core is to handle and use the relationship between the three primary colors and the black version. According to the characteristics of the manuscript, the conditions of printability, and the customer's requirements for the product, can be summarized into two categories:

1. Manuscripts are mainly copied in color. This type of manuscript generally has a wide range of density, rich layers, and bright colors. In the picture, the primary colors and the inter-colors are relatively large. At this time, the tri-color version should be reused. On the basis of maintaining the necessary tone, the main tone of the picture should be expressed in the tricolor version as far as possible. Relatively long tone, basic color enough, the opposite color to be appropriate or not, the black version is relatively short, the background removal is relatively small, the black version to increase the absorption of the medium to dark tone, to strengthen the role of the level, stable Medium-to-dark tone color, increase the image contrast effect, improve the adaptability of printing. Some black and white tones may be short and shallow (0% to 50%), some may be short and moderate (0% to 65%) and some may be shorter and shorter (0% to 80%), regardless of the darkest version. How many dot areas, and the starting point is to start from the middle part, focusing on the role of skeleton, make up the reward effect.

2. Manuscripts are mainly copied in layers or non-colors. This type of manuscript is generally rich in layers, simple in color, elegant, mainly in a non-color tone (such as coke, thick, heavy, light, clear ink in the Chinese painting anti-light), copy should reuse the black version, the main tone of the image by Black Edition performance, if necessary, can increase the gray version of the auxiliary. The black tone is relatively long, and the three primary colors are relatively short in terms of satisfying the primary colors and the inter-color requirements, and the amount of background removal is correspondingly increased, which is favorable for plate making and printing, and is beneficial to the main tone of the reproduced image. Prevent achromatic tone yellowing, purple or reddish.

Nature is very rich in everything. According to the CY/T23 "Printing Manuscript Classification" standard, manuscripts are divided into physical objects, drawings, photographs, electronic manuscripts, etc. In the terms of image manuscripts, prints are also regarded as manuscripts. Each type of manuscript has its own characteristics. When a manuscript of the same type is prepared, different customers have different requirements. Although data is used on the equipment or in the software, the data used is adjustable, so it is difficult to give quantitative requirements. Only the specification requirements can be given.

For manuscripts with color as the main subject, the three primary colors should be used reasonably, mainly in the three primary colors, with a correspondingly long tone, and a black version as a supplement. The tone of the manuscript should be relatively short, and the amount of background removal should be relatively small; manuscripts with the main layer or non-color as the main body should be used. The black version should be reused, the tone is relatively long, and the tones of the three primary colors should be relatively short, and the amount of background removal should be relatively large. If the three primary colors have long steps and the black tone is long, the images will be gray, dark, and difficult to print. If the three primary color version has a short tone, the amount of background removal is large, and the black version is also short, the image will be gray, flat, thin, discontinuous, and poor in three-dimensional. Therefore, according to the characteristics of the manuscript, the printability conditions, and the customer's requirements for the product, in the implementation process, the relationship between the three primary colors and the black edition should be handled scientifically and scientifically, and the amount of undercuts should be reasonably used to achieve product quality and efficiency improvement. purpose.

Reprinted from: Print Channel