How much do you know about printing color sequence?
Time:2022-07-29
Views:2641
First, the main reasons for the printing color sequence:
There are three main reasons for the arrangement of printing color sequence:
1. The influence of ink overprinting and the shortcomings of ink coloring material itself;
2. The quality of paper;
3. The ability of human eyes to recognize colors.
The most fundamental reason is the incomplete transparency of the printing ink itself, that is, the covering power of the ink itself. The printing ink has a certain covering effect on the ink layer of the first printing, so that the color of the printed matter always focuses on the performance of the latter color, or the mixture of the after color and the front color.
Two, the factors affecting the printing color sequence:
1.From the ink transparency consideration
The transparency of ink and ink pigment covering power. The so-called ink cover power refers to the cover layer of ink for the underlying ink cover ability. Covering power is poor ink transparency, covering power is strong ink brightness. Generally speaking, should be the poor covering power that is the transparency of the ink on the back of the printing, so that the front printing ink gloss cover in order to facilitate the reproduction of color. Ink transparency strength relationship: Y>M>C>BK.
2.From the ink brightness consideration
Low brightness first printing, high brightness after printing, that is, deep ink first printing, light ink after printing. Because the higher the brightness, the higher the reflectance, the more vivid the color is reflected, and the light color is overprinted on the dark color, and the trace overprinting is not very conspicuous; If you put a dark color on top of a light color, it will be completely exposed. In general, ink brightness size relationship: Y>C>M>BK.
3.From the ink drying speed consideration
Slow drying speed first printing, fast printing later. If the first printing fast, for monochrome machine, because it is wet dry, it is easy to glass, is not conducive to fixation; For multicolor machine, not only is not conducive to the overprinting of the ink layer, but also easy to cause other ills, such as the back of the dirt and so on. The order of ink drying speed: yellow faster than red 2 times, red faster than green 1 times, black the slowest.
4. Consider the nature of the paper
1) the surface strength of the paper.
Paper surface strength refers to the paper surface fiber and fiber, fiber and glue, filler between the binding force. The greater the binding force, the higher the surface strength, often in printing paper surface dedusting, hair loss degree to measure. For good surface strength, that is, the binding force is large, not easy to depowder, hair off the paper, we should first print the viscosity of ink, viscosity of the first color printing is also conducive to overprinting.
2), for the paper whiteness is good, should be printed in dark color after light color.
3), for rough and loose paper, the first printing light color and then printing dark.
5. Consider the share of network area
Dot area small first printing, dot area large after printing. In this way, the printed image is more colorful, more vivid, but also conducive to dot reproduction.
6. Consider the characteristics of the original manuscript itself
Generally speaking, the manuscript can be divided into warm tone manuscript and cold tone manuscript. Warm tone based manuscript, should first print black and green, after printing magenta and yellow; For cold tone based manuscripts, magenta should be printed first, followed by black and green. In this way, the layers of the main tone can be more prominent.
7. Consider mechanical properties
Due to the offset printing press model, its overprinting method, effect also has some differences. As we know, monochrome machine is "wet press dry" set, overprinting form, and multicolor machine is "wet press wet" and "wet press dry" combined set, overprinting form, their set, overprinting effect is not the same. The usual monochromator color sequence is: first printing yellow, then printing magenta, cyan and black respectively.
Three, the printing color sequence must follow the principle:
Printing color sequence will directly affect the quality of printing products. In order to obtain good reproduction effect, the following principles must be followed:
1.According to the lightness of the three primary color arrangement color order: the lightness of the three primary ink is reflected in the spectrophotometric curve of the three primary ink, the higher the reflectance, the higher the ink brightness. Therefore, the lightness of primary ink is; Yellow > cyan > magenta > Black.
2.According to the transparency of the three color ink and cover power arrangement color order: ink transparency and cover power depends on the difference between the refractive index of pigments and connecting materials. Covering stronger ink on the color after the color of the larger impact, as a post-printing color overprinting is not easy to show the correct color, can not achieve good color mixing effect. Therefore, poor transparency of ink printing, transparency after printing.
3.According to the size of the dot area arrangement color order: in general, the dot area is small first printing, the dot area is large after printing.
4. Arrange the color order according to the characteristics of the original manuscript: each manuscript has different characteristics, some are warm tone, some are cold tone. In the color sequence arrangement, to warm tone mainly printed black, green, red, yellow; To cold - based printing red, after printing green.
5. According to the different arrangement of the color sequence of the equipment: under normal circumstances, the printing color sequence of the monochrome or two-color machine is appropriate to alternate the light and dark colors; A four-color press usually prints dark colors before light colors.
6. According to the nature of the paper arranged color order: paper smoothness, whiteness, tightness and surface strength are different, flat, tight paper printing dark, light after printing; Thick, loose paper, first printing bright yellow ink, after printing dark, because yellow ink can cover off paper hair and powder and other paper defects.
7. According to the drying performance of ink arrangement color sequence: practice has proved that yellow ink than magenta ink drying speed nearly twice faster, magenta ink than green ink twice faster, black ink fixation is the slowest. Dry slow ink should be printed first, dry fast ink after printing. Monochromators usually finish with yellow to prevent vitrification so that the conjunctiva dries quickly.
8. According to the flat screen and field arrangement color sequence: the reproduction of flat screen and field, in order to obtain good printing quality, so that the field flat clothes, bright and thick ink, generally printed flat screen text and text, after printing field structure.
9. Arrange the color order according to the light color and dark color: in order to make the printed matter have a certain luster and print the light color, print the dark color first, then print the light color.
10. The green layout text area of landscape products is much larger than that of magenta edition. According to the principle of post-printing of color plate with large graphic area, black, magenta, cyan and yellow sequence should be used.
11. The products based on text and black field are generally green, magenta, yellow and black, but the black text and design can not be printed on the yellow field, otherwise due to the low viscosity of yellow ink and the high viscosity of black ink, the reverse overprinting will occur, resulting in the black can not be printed or printed incorrectly.
12. For the four-color overprint area is very small screen, the color sequence can generally use the principle of color plate printing after the large graphic and text area.
13. Gold and silver products, because the adhesion of gold and silver ink is very small, gold and silver ink should be put in the last color as far as possible, in general, it is not suitable to use three times overlapping ink printing.
14. The color sequence of printing should be consistent with the color sequence of proofing as far as possible, or it will not catch up with the proofing effect.
If it is a 4 color machine, printing 5 color live, it is necessary to consider the problem of embossing or overprinting, the general bite position of the color overprinting is more accurate. If there are overprints, we must make a trap, or overprints are not allowed to leak.