How to prevent color shift in prints (top)

Any kind of color prints is completed by printing inks of yellow, magenta, cyan, and black in a certain plate making process and printing color sequence. How to prevent prints from appearing color casts and accurately reproducing colors and layers is a problem that should be noted in the printing process. If these aspects are neglected, the quality of printed matter will be affected and the color and level of prints will be deviated.

Color deviation: It refers to the difference in color when the printed product is compared with the original or the proof.

Prevention of color cast in the process technology should pay attention to two reasons. (1) Arrangement of plate-making cable angles. (2) Arrangement of printing color sequence.

A: Arrangement of screen angle in the process of color plate making

In the process of color plate-making, if the arrangement of the screen angle is not correct, it will affect the printing color effect, and when it is serious, it will also produce a moiré pattern.

The current four-color plate printing is based on the primary colors of yellow, magenta, and cyan, which represent the ever-changing colors of the picture. The black version only aggravates the dark tone and plays a role in the skeleton. From the perspective of color rendering performance, yellow, magenta, cyan, and black colors have the weakest visual sensitivity in yellow, followed by magenta, cyan, and black. Since the line of sight of a person is particularly sensitive to a dot at a 45° angle, the dot of 0 or 90 degrees feels worse, and for a dot angle of 15 or 75 degrees, the human eye feels normal.

In view of the above factors, the angle of the screen of each color version should be determined according to the main color tone of the original. Therefore, the main color plate of the original should generally be made 45°, 75°, and 90° in other colors.

For monochrome halftone prints, we should use 45-degree outlets. However, for multi-color halftone prints, the angles of the various editions must be staggered. The commonly used color screen angles are as follows:

1. For two-color printing, the main color version or the dark color version is used with a 45° screen angle, a sub-color version or a light color version with a 15° screen angle.

2. For three-color printing, the main color or dark version uses a 45° screen angle, and the other two versions use a 15° and 75° screen angle.

3, four-color printing, the main color version with a 45 ° screen angle, the yellow version with a 90 ° screen angle, the other two colors with 15 ° and 75 ° screen angle.

According to the screen main color arrangement network line angle has the following several kinds of situations:

(1) If the main color of the screen is a red warm tone, it can be set as: 45° for the magenta version, 15° for the black version, 75° for the cyan version, and 90° for the yellow version.

(2) If the main color of the picture is a cool cyan tone, then: 45° for cyan, 75° for black, 15° for magenta, and 90° for yellow.

(3) If the main colors of the picture are black Chinese paintings, then: Black Edition 45°, Youth Edition 75°, Magenta Edition 15°, Yellow Edition 90°.

In the normal printing situation, according to the above method to arrange the network line angle, and then correctly arrange the color sequence, can effectively prevent the printed products from color cast. Make the print colorful and clear.