Advantages and Solutions of Screening Technology (Part 2)

Heidelberg applied this technique to their ctf imaging machine a few years ago. Creo combines this precise network of dots, the company's Staccat0 screening technology, and consulting services to enable FM screening technology to recover again. It advocates controlling on-machine profits, including reducing the amount of ink used, obtaining higher color stability, and making ink easier to reach balance.

Better printing process stability has gradually shifted the offset from the newspaper printing of 65 screen lines per inch to 100 to 110 lines per inch (40 to 44 lines per cm). In commercial offset printing, the number of screen lines is increased from 133 lpi (541/cm) to 1751 pi (70 l/cm), and even very high quality printing requirements can reach 200 lpi (80 l/cm).

Alternatives to AM

A similar approach to FM as an alternative to the AM screening technique is to use very fine screens for screening. This method has become widespread in Japan and is commonly used by many professional printing companies in the Western Hemisphere. This method usually uses a line number of 250-350 lpi or even higher to optimize the printing effect and achieve a clearer, more elaborate effect through the high-density ink.

Breakthroughs in the number of ultra-high-gauge lines have encountered the same problems as FM, such as harsh process conditions and the need for high-resolution scanning to generate maximum profits.

In many places in Europe and the United States, 300 dpi scans and modest false light masks are often the default settings, while in Japan scan standards are set at 350dip and slightly higher levels of unclear masks to cater for higher screen lines. The request. Associated with the number of super-high screen lines is a higher image resolution, which means that more gray levels can be generated.

For 4,000 dpi superhigh screens, the imaging process is significantly slower than the 2,400 or 2,540 dpi more commonly used by the Western world in AM and FM screening.

In the East, Fuji Corporation proposed a Co-Res screening method using a traditional screening angle, which can achieve a 300 lpi effect with a platemaking machine that uses a relatively high resolution and low resolution to achieve this effect.

To date, the technology is still limited to use in Fuji's Corporate Rip and platesetters. The most immediate advantage is a leap in the overall production volume, because there is less data to be processed, and it is not necessary to change the operating habits of the printing press because the screen angle and dot are exactly the same as the original.

A few years ago, companies like Barco and Screen were looking for the ideal way to combine FM and AM screening on the same image. This approach uses the most suitable AM ​​screening in both flat and skin tone locations, and FM screening in fine detail and moiré-sensitive object areas.

Interactive mask

The disadvantage of the hybrid screening method is that it requires interactive masks on high-end workstations, such as Screen's TaigaPress. Therefore, the labor intensity is high, and people are suitable for high-value printing projects. For packaging applications, printing methods with more than four colors are generally used. For the more coarse screen printing lines for flexo printing, Barco's warehousing of Artwork Systems has developed a corresponding hybrid screening method to not only prevent the occurrence of moiré patterns. You can also produce more detail in lighter and darker areas for more clear, more saturated printing.

This hybrid screening method can provide FM details and continuous tone reproduction of bright and dark areas without affecting most flat tone and midtone grainy graphics because these are implemented using AM screening. .

In the area of ​​newspaper printing, Aafa completed the test of the hybrid screening technology Spekta, which has been tested in Norway, using FM CristalRaster outlets in some regions and AMABS screening in the middle portion.

Screen Corporation has recently introduced Spekta, a new hybrid screening technology to achieve the best quality of its thermal Ctp imagers. Spekta screening technology effectively combines the advantages of FM and AM screening in dot formation, color mixing, moire and global operation compensation on the press.

As with other hybrid screening methods, Spekta uses FM screening for O-10% and 90-99% of the replication area, and AM round-net screening for the range of 10-90%. Since all the dots are randomly distributed within the total dot area, there is no limitation of the screening angle between different colors, and therefore no problem of moire occurs when colors are mixed. Spekta can provide an optical effect comparable to 300+1pi compared to other high-mesh screens. There is no productivity limitation, but 2,400 dpi is used in standard image setting areas such as 175 lpi (70 l/cm). network.

After successful testing, some European users, such as Zwaan Offset in the Netherlands and Fulmar Printing in the United Kingdom, appreciated the way in which the clear detail offset provided by FM screening was combined with the overall process control provided by AM screening. Both of these methods are well known to printing companies.

The best screening solution

Under normal circumstances, adding text to the image will give better results, such as wine labels and maps. The use of Screen's Spekta Screening Technology eliminates visible rose spots and moiré, and together with Screen Taiga and Trueflow, provides users with the unique PlatRite thermal imaging machine, which is a versatile, most suitable screening solution.

After the end of the screening war in the 1980s, the industry experienced a relatively quiet period.

New technologies related to thermal ctp imaging technology can now produce clearer, more replicable dot quality. Based on this, prepress customers are constantly looking for the best screening mode to get the maximum productivity in order to achieve the best reproduction effect in the easiest way.

In the process of printing and copying, outlets are undoubtedly the most important issue. Combining AM and FM technologies together will certainly produce better results.