High-line printing cheats! The old and new employees of the carton factory must have one person!

Experts from China International Corrugated Experts Committee, Qiu Yongshi, shared with us the high-line printing cheats!

First, the three primary colors and color material mixing law

The color of nature is rich and colorful, but in the printing industry, it is impossible to prepare all the colors in the form of pigments. Instead, some common colors are selected as the basic reserve of color materials, and other colors can be mixed by using basic colors. get.

In the printing industry, only yellow (Y), magenta (M), cyan (C) and black (K) are often used as basic colors for print reproduction, and other colors are yellow (Y), magenta (M), The blue (C) three-color inks are mixed in different proportions, which makes it possible to print and reproduce complex colors and is very convenient. Therefore, the three colors of yellow (Y), magenta (M), and cyan (C) are called the three primary colors of the colorant.

If you mix the three primary colors of the same amount of colorants together, there are the following mixing rules:

Magenta (M) + Yellow (Y) = Red (R)

Magenta (M) + Blue (C) = Blue (B)

Yellow (Y) + Green (C) = Green (G)

Magenta (M) + Yellow (Y) + Blue (C) = Black (K)

The following figure shows the mixing rules of the three primary colors of the colorants.

If you change the mixing ratio of the two primary colors or the three primary colors, you can get other different color materials.

Second, understanding network

1, what is the network

Dots are pixels that make up the dot image, which reproduces the shade and effect of the original by changing the area and/or the amount of ink. All halftone printing is achieved through dots.

2, know the network

â– Shape shape

The dot shapes include circular dots, square dots, diamond dots, cross-shaped dots, oval dots, and linear dots. In general, we use circular outlets.

â–  The size of the outlet

The size of outlets is also called the area of ​​outlets. It is determined by the coverage of outlets and is also called the ink ratio. They can generally be divided into 101 grades, varying from 0-100. The outlets can also be represented by the number of outlets. 10% outlets are 10% outlets, 20% outlets are 20% outlets, and so on. A network with a coverage of 0% is called "absolute" and a network with a coverage of 100% is called "in the field."

â–  Lines of outlets

Density of dots is represented by the number of lines, and the unit is line/inch or line/cm. The more lines, the smaller the network points, the richer the level of picture performance; on the other hand, if the number of lines is small, the picture appears rough. When the distance between the network points is less than 1' for the human eye, the distance between the network points is less than the visual resolution limit, and the human eye cannot see the network points.

â– Network point of view

The arrangement of dots of various colors is neat and regular, and the change of the dot angle can be represented by 0°-90°. The angle difference between the dots has the following rules:

1 The intersection angle between the dots of different colors is 30° (or 60°), and the minimum is not less than 22.5°, except for yellow and light colors;

2 The commonly used dot angles are 7.5°, 37.5°, 67.5°, 82.5° and 7.5°, 22.5°, 52.5° and 82.5°;

3 The angle of the dot pattern of the overlapping pattern should be different from the main color of the product by 30°, otherwise it is easy to produce moire.

3, network color principle

Separation is only the decomposition of the color of the original, when printing mixed with the original shade, different shades of color, is to rely on network to complete. We call it dot coloring. In color printing, different colors of printing plates are formed with different halftone angles to form a rich network tone, and through the control of the dot size, the ink color is different in different areas, resulting in different shades. Shades of different colors. This is the principle of dot coloring.

Third, AM screening and FM screening

The outlets are divided into two types of AM outlets and FM outlets according to their different characteristics.

1, AM screening

AM screening refers to the spatial distribution of the outlets in an orderly manner and the number of units within the area is constant, and the reproduction of the tone is achieved by changing the area of ​​each outlet. It is an area-modulated outlet and is a common screening method in modern printing. .

2, FM screening

FM screening dots refers to the spatial distribution of random (random distribution) and each dot area remains unchanged, the space by changing the intensity of dots (i.e., changes in the spatial frequency distribution network) reproducing tonal level, density modulation genus Type outlets .