Prepress processing screening method selection

Screening methods From the initial photographic screening to the current laser electronic screening, there have been a number of screening technologies such as rational meshes, irrational meshes, and composite meshes.

I. AM screening (SAM)

AM screening technology is based on the center element of the grid. The distances between the centers of two neighboring nodes are not changed. The arrangement of the dots follows a certain rule. The shape of the dot is an artificially designed point type. The size of the pixel value controls the size of the dot area, and it expresses the depth and the lightness of the image layer by changing the dot size under the condition that the number of screen dots is constant.

The computer AM screening and the electronic color separation machine are basically the same. The fine adjustment of dot shape and dot shape adjustment algorithm is a difficult point in the AM screening technology.

In short, due to the regular distribution of dots, it is determined that the interference screening is easy to occur when AM screening is used in multi-color overprinting, and the separation screen angle must be strictly controlled.

Second, frequency modulation screening (SFM)

FM screening technology is the idea of ​​some of the particles as independent pixel units. They are randomly distributed in a specific unit area, and their area varies according to the calculation method.

Compared with AM screening, FM screening has many advantages. In the field of offset printing, flexographic printing, news printing, etc., there is an excellent development prospect. However, due to the small number of ink-jet screens for FM screens, the requirements for paper, ink, and equipment are high, and there are problems in promotion and application.

Third, high-fidelity true color screen technology

In order to further improve the level of printing technology, improve the resolution of printing equipment, give full play to the advantages of computer-based platemaking technology, and fundamentally improve the reproduction quality of printed matter. As a result, high-fidelity, true-color screening technology has been produced. High-fidelity network is a new standard set for FM network technology and is a software-only method. High-fidelity true color adopts frequency-measuring dots and uses color separation technology of more than four colors. Compared with four-color screening technology, there are significant improvements in color reproduction range, printing density, clarity and gradation. High-fidelity screening technology is the mainstream of future screening technologies.

Reprinted from: Printing Industry Channel