The trend of the Shiny Golden Inner Frame FM screening (Part 2)

The trend of the Shiny Golden Inner Frame FM screening (Part 2)

Five. Network increase and FM network level compensation

In the printing engineering, it is almost impossible to avoid the increase of the dot. The phenomenon of dot increase can be divided into physical dot increase and optical dot increase. Both -@ species occur at the junction of the line part and the non-line part. The amount it occurs will be the sum of the surrounding length (the thick line in Figure 4), depending on the printing environment of the machine type and drum arrangement of the press (see Figure 4).

This kind of network increases, AM network and FM network is very different. What usually becomes a problem is physical dot enlargement. Because the sum of the surrounding length of the FM screen is certainly long, if it is printed without compensation, there is no doubt that the FM screen side is deeper than the AM screen, and its tone is printed. In order to reduce this tone difference to the lowest possible degree to obtain a natural effect, the tone is compensated from the CTP when the image is output to the plate at the time of FM screening. Staccato's occasion is to calculate the difference in reproducibility between AM and FM screening, draw a compensation curve, and then respond with a compensation curve for the 4 colors of YMCK, so it is easy to match the tones well.

6.FM mesh color brightness

It is generally believed that FM screen printed matter, its color is always bright. This is caused by the effect of optical dot enlargement. As mentioned above, dot increase occurs at the junction of graph and non-graph parts. Like physical dot increase, optical dot increase also occurs at the junction. The physical dot increase is actually the phenomenon that the ink image (ink film) is crushed by the printing pressure, and the optical dot increase seems to be a phenomenon that is reflected in the human eye.

On AM screen printing, the printed image has a cloudy feeling compared with the actual original manuscript. This is not the turbidity of the ink itself, but the turbidity felt by the moment the white of the paper around the ink image is reflected into the human eye. As can be seen from Figure 6, when the dot increase occurs, compared with AM mesh in this aspect, the amount of dot increase is larger, so the naked eye is difficult to feel the white paper, thereby reducing the color turbidity. According to this phenomenon, the color of the ink image looks bright.

In addition, Staccato occasions, the work on the configuration of various colors, relying on the reduction of overlap, thereby reducing the reflected light from the white paper and the overlap of ink caused by the color turbidity, and at the same time, the ink film is thin and improve the color saturation of the middle tone.

7.FM mesh and ink consumption reduction effect

One of the biggest advantages of FM screening that AM screening does not have is the reduction effect of ink consumption. It has been mentioned earlier that AM screening is different in the size of the dot, the ink is viscous in circulation, and the thickness (amount of ink) of the ink film is different on the part of the big idea and the small idea. Therefore, the amount of ink is not uniform, and the amount of ink supply has to be adjusted during the printing process (flipping the ink key). On the other hand, FM screening is because it is a fine point, the amount of ink has a certain limit, the ink film is also thin and uniform, and the minimum amount of ink can be supplied to print well, thereby saving the amount of ink consumption.

According to the printing trials of Creo's official presses, 18-34% of ink savings have been reported. Taking into account the increase of the dot, FM screening and AM screening as the same reproduction, compared with the compensated plate image area (inking area), there is a 10% area difference. In fact, the amount of ink consumption measured on the web offset press of the printing company also results in an average savings of 15-17%.

In any case, the printing aspect also shows an effect that cannot be ignored from the point of view of saving ink consumption. However, this is from the point of view of photography and uniform density and other toned images, if it is text or only for the field of low print, then FM screening and AM screening are exactly the same. Moreover, even if there is a tone of the image, due to the depth of the tone, the reduction effect will be different.

Viii. Concluding remarks

In the current printing industry, which does not expect major technological innovation, as a strategy for printing product differentiation, it is true that with the popularization of CTP, the effect of FM screening is reevaluated. However, it is still in the early stages and there are still many issues to be solved.

The current prepress engineering and printing workflow is mainly a process centered on AM screening, among which, only the conversion of screening to FM screening will bring a lot of problems to be solved in color reproduction and other aspects. When solving these issues, so that FM network become a perfect workflow, not only to improve the FM network software, more importantly, to improve ink, paper, plate material, water, rubber blanket, printing press and other aspects, in the face of these issues to be solved, looking forward to the relevant manufacturers to adopt a coordinated system, is the best policy.