The Trend of FM Screening (I)

I. Preface

Recently, with the popularity of CTP, FM Plus has been taken seriously. FM screening is a screening technology developed by Gerhard Fischer et al. in 1984 in Germany. Diamond Screening was introduced by Linotype Hell in 1993, and CrystalRaster was published by AgfaGevaert. Since then, it has been transmitted to Japan as a new screening method. .

GreoJapan once paid attention to the new printing performance technology. FM Screening is the key to the technology that is used to accurately reproduce the layout with subtle ideas. However, it was at the time that the PS version had just been put on the market, and it was in the transitional period between the transfer of the plane and the intaglio to the PS version. It had not yet provided a means for stabilizing the printing plate, and finally this new technology was blocked. However, since the development of the CTP, it has been possible to provide a stable printing plate so that the FM screen can be revived.

In the original FM screening, there were 1) bright spots with obvious unevenness; 2) intermediate tone was blocked, and printed spots were not easy to print. Disadvantages often came from the printing department. Now these shortcomings have been eliminated. It has become a special tool for the differentiation of printed products and has been reassessed. Currently, various high-precision screenings have been published by pre-press related manufacturers. The main brands of FM screening and hybrid screening that can be seen frequently in domestic and foreign markets are listed below:

Fuji Photo Film: TAFEETA
Da Nippon Screen: Fairdot / RandotX
Heidelberg: Satin
Agfa Gevaert:Subima
Creo: Staccato

Each of the above has its own advantages and disadvantages, but as a help for high-grade printing and high-precision printing technologies, there is great potential for future development. Here, the trend of FM screening is tentatively centered on Crete's Staccato.

II. Point structure of AM screening and FM screening

This article omits a detailed description of the principles of FM screening. After comparing the AM screening with the earlier FM screening (1st generation), a brief introduction to the difference between the 2nd generation Staccato is provided. .

As we all know, AM screening is an orderly arrangement of outlets. According to each outlet, 0-100% of the extension can be used to express the depth. There is a regular arrangement where households feel that they feel equal, but this equality may lead to disasters. Compared with this, FM screening is based on the same size of fine dots scattered regularly, according to its density to show the depth.

At the beginning of the development, the FM screening of the first generation was called. Due to the improper distribution of ideas, there were dense parts and scattered parts in the middle tone. This is because the area of ​​non-graphic lines is not uniform and the dampening solution cannot be evenly supplied, and ink is applied to the portion with less water supply, causing ink blocking. This has caused the phenomenon of ink blocking in the middle tone, which has become a difficult factor in printing projects.

The second-generation FM screening, represented by Staccato, has been improved by the improper mediation.

A closer look at the idea of ​​the structure of Staccato's midtones, as if the snakes were forming a unique pattern. According to this pattern, the area of ​​the non-graphic part is evened out, which contributes to the equalization of the water supply, and the phenomenon of ink blocking is eliminated, so that the intermediate printing is smooth.

In addition, what is considered is the quality of the FM screening, how to reproduce the homogeneous and fine dots stably on the printing plate. This was made possible by the investment in CTP. In particular, the high-performance IR laser light source called SQUAREspot installed in Creo's CTP was responsible for maintaining the high quality of Staccato.

III. Specialty of FM Screening

Let's introduce the special features of FM screening that AM screening does not have. Because FM screening is based on fine-grained, regular arrangements, it has many of the features that make up for AM screening problems.

Here are a few of them:

1) No moiré 2) wide reproducibility of color reproduction during screening 3) Can show a photo-like smoothness 4) Clearly reproduced small colored text 5) Clear text in the net 6) 4 colors Spot color effect obtained by plate printing 7) Little color unevenness in printing process 8) Shortened ink drying time 9) Effect of saving ink consumption

4. Staccato's idea size and its use

Staccato can choose a variety of sizes for different purposes (see Table 1)

2400 dpi

Brightness of the idea size

Conversion of AM points for bright spot

Midtone Converted AM Lines

Staccato 10

10 m

1% 240 lpi

480 lpi

Staccato 20

20 m

1% 120 lpi or 1.5% 150 lpi

385 lpi

Staccato 25

20 m

1% 120 lpi or 1.5% 150 l pi

240 lpi

Staccato 35

30 m

1% 80 lpi or 2% 110 lpi

240 lpi

Staccato 36

30 m

1% 80 lpi or 2% 110 lpi

205 lpi

Staccato 40

40 m

2% 85 lpi

190 lpi

Staccato 70

60 m

2% 60 lpi

120 lpi