As one of the three primary colors of yellow, seems to be different from other colors. Because offset printing, most of the yellow ink as the first color to print. To this end, yellow version of the ink, the reproduction order harmonic minor level, to master just right. After all, the first color version is the foundation. Therefore, the yellow ink in the printing is very important.

First, why the color yellow is often used as first used by the general yellow color printing ink the pigment is an inorganic pigment is chromium salt, divided into lemon yellow, light yellow, medium yellow, dark yellow, orange, etc. 5, the proportion of 5.6 to 6, with a little oily, heavy, coarse, hiding power characteristics. Often as the first yellow ink color printing, mainly for the following considerations. 1, transparency and printing from the ink color sequence of relations, under normal circumstances, should be strong hiding power differential that is transparent printing ink on the back. The yellow ink hiding power, if it overlay the other ink on the print will lack luster. Such as: the first yellow ink color printing, the second magenta ink color printing, so printing out the red works well; the other hand, the first printing of red ink, and then trapping with yellow ink, printing out the red effect on the poor. Of course, with the continuous improvement of printing ink, yellow ink is also increasing transparency in order to offset domestic light quick-drying inks, for example, its transparency to better, if the selection of high quality transparent overlay of time after the ink color sequence, the effect is also possible. In fact, many manufacturers have chosen this color sequence. 2, the first yellow ink color printing can play fill the role of a rough surface of paper, and because it is less oily, the next color ink easy to overlay up. 3, the depth of ink level from the point of view, in a dark light on the overlay, overprint trace if allowed, is not very conspicuous. In contrast, in light of deep color overlay, overprint if allowed, will be exposed. Therefore, the use of red version of stacked yellow version, the overlay appears difficult to detect trace are not allowed, while the red version with a yellow version of the stack, if the overlay are not allowed, then it is easy to observe it.

Second, the print yellow ink what issues should pay attention to than the yellow light, his eye is not sensitive to the time of printing, the size of ink on the yellow version of the master and the fine level of control of outlets than the printed version of red, blue version The following is much more difficult when printing yellow ink several aspects need special attention:

1, before the formal printing, plates should be checked, the method is 5 to 10 times the magnifying glass to identify the depth of the plate, to see whether the electrical outlets in four-color film of the same size network. Under normal circumstances, allow the plate of the network than the electrical sub-film slightly smaller, if the printed version of the network score bigger network color film, then the plates drying out too. After checking the depth of the plate, but also look at whether it is the quality of network requirements.

2, the yellow ink can be divided into three colors, namely: slightly yellow blue ink, the yellow ink, slightly red in the dark yellow ink. As for the offset when the use is a yellow ink, according to the original hue to be. Yellow version in India, to estimate the changes to the ink itself, the change after drying, such as the neutral color yellow ink dries more easily flushed and so on. In the offset boot, according to the kind of proof ink monochrome.

3, check the yellow version of the printing process ink, we should pay attention to the surrounding light. For example: incandescent light orange yellow, blue-violet fluorescent light side point, in such a light color will occur under the observation of visual bias. In addition, the yellow, they often use the blue glass. Because in the case of non-uniform light source, easy to judge is unclear, while the blue (yellow complementary color) glass to avoid the error caused by source instability. Or check the yellow, wear blue sunglasses.

4, in normal print, you should see ground sheets, printed with the proof will be carefully controlled. Control method is to print on the same sample and sample location adjacent to the light source for comparison. Is best under natural light in the workshop to identify the depth of ink, overprint color cast and so on. The only way to ensure consistent print and ink proofs.

5, in the control of yellow ink ink, should ensure consistent color proofs printed like the reflection density. If it is possible, use color reflection densitometer, measuring and calculation of the yellow in order to achieve data and standardization of the technical quality of management. If the can well be measured to calculate ink, so that evidence-based, you can increase labor productivity, saving raw materials, by a fundamental change that vision, to use their experience to control the size of ink, dot gain, quality management and other backward methods.

6 color offset press in the Y, M, C, K color order printing, printed yellow is a critical first step, we must control the amount of yellow ink in the ink. Large amount of yellow ink ink, after printing the magenta, blue, black ink must be followed to increase the amount of ink, or color cast will appear the phenomenon. If the main characters in the picture, the skin color is a printed copy of the key, if the large amount of yellow ink, and magenta ink small, yellowish skin color printed characters, it will give people the feeling of healthy skin. If the landscape, places reflect the natural landscape, the main colors cyan, yellow for the secondary colors. Printing landscape is very important printed yellow, blue sky, white clouds blue version is based, and the green trees and flowers are yellow and green version of network version of the presentation of the color overlay, yellow version of the ink volume, ink blue version of a small amount of The green grass will yellow.

In short, the print version to master the yellow ink size. Avoid large ink, dot gain, dirty version, paste version, imprinted slow drying, ink is small, dull ink, dot is not strong, subdued hair is true, network and field is not smooth, clear and other defects.

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