Advantages and Solutions of Screening Technology (I)

The AM and FM mentioned in the printing industry are not as simple as the wavelength of a radio. In today's complex, fully automated prepress workflow, the hot topics of discussion are focused on issues such as PDF, JDF, XML, CMS, and ICC. Screening is no longer the technology most concerned by prepress specialists.

However, recent developments indicate that screening, as well as other forms of network formation, remain the top concerns for prepress workflow and output system manufacturers and distributors.

Important production tools

The benefits of optimizing screening technology are to bring more vivid printing products to the printing industry, with clearer details, no more moiré patterns, and enhanced stability of the process. Companies that ignore this technology miss out on a very important issue. Production control tools.

Let us first review the development of digital screening technology. It has evolved slowly from the process of glass and catenary screens used in the formation of simulated networks. From the early days of offset printing technology, printing process experts have been experimenting with dot shapes, angles, and screen lines, hoping to optimize the effectiveness of the printed matter and control the process. Digital screening provides us with a possible method of physically forming network points, making the process constraints no longer a problem.

When dtp (desktop publishing, desktop publiShing) appeared, the early Postscript Rip could achieve four-color and multi-color digital screening, but the quality was lower than digital screening of analog screening and dedicated high-end color systems. Experienced prepress operators may still remember the extensive and intense discussion of “screening” in the late 1980s.

Later, a revolutionary change occurred in the optimization of network configurations, which provided more screening angle options than Postscript level 1. At the same time, prepress equipment manufacturers started to pay attention to Postscriptrip and applied their rich screening knowledge to the desktop publishing system.

The real revolution is to adopt: FM or random screening, although it is not a new idea. In the 1980s, it had been used in digital printing processes where the quality of dots was not high. Instead of using different dot sizes to simulate different continuous tone, it used the same relatively small dots. Between the intervals to reproduce the tone.

The FM/Random Screening was just launched at the time of the most intense war on the Internet. It received a lot of advertising and gave great expectations. Since then, the traditional screening method has been named AM (Amplitude Modulation) screening to distinguish it from FM screening.

Clearer effect

Compared with AM, the advantage of FM is a clearer effect, because extremely small dots can produce more hues; ensuring no moire between colors and patterns, making the printing process more stable. However, when it applied FM screening to a wider range of non-industry approaches, it encountered many obstacles.

The disadvantages encountered in the early 1990s were that it was very difficult to process in computer-to-film (ctf) environments and that there was no exposure range for printing plates; particles were generated in the gray midtone and flat net areas. Patterns; and it is difficult to compensate for chromatic aberrations on the press by using ink thickness variations. Early adopters of this method were able to insist on using it.

However, in the past decade, a small number of prepress and printing companies have begun to use the FM screening technology in a tacit understanding to produce higher quality prints. Artistic books and high-gloss catalog products with more prone moire objects, such as textile images, speaker's pupils, and architectural designs, all benefited from FM screening technology and became a technology they were happy to use.

Simplify the process

Because ctp technology simplifies the process, it plays an important role in the recovery of FM screening technology. In addition to film, dust and registration problems have become factors that hinder the development of FM technology.

Since cpt technology is used without much consideration of film edges (thickness) or dust particles, smaller FM dots (usually 12 to 80 microns in offset printing and 70 microns in flexo and newspaper printing) can be printed directly Version is formed.

Another advantage of Ctp surgery is that a harder dot can be formed on the thermal plate for better printing results. Particles composed of laser beams can form screened dots that are predictable in imaging and printing. Any edge of the dot formed by the unfixed layer of the residual plate will not form an irregular printing effect.

Creo strongly recommends using Turbo or SpuareSpot screening technology to take a step forward in the quality of hard spot. This technique improves the accuracy of the screen dots by adopting a higher resolution in the main scanning direction (the circumference of the exposure roller) than the direction to be scanned (the direction above the roller). Compared with the conventional dot-mapping (2,400×2,400 dpi) technology of the same size, a screen dot consisting of more particles can achieve higher resolution (9,600×2,400 dpi).