Reproduction technique and performance of special

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The reproduction technique and performance of special colors above four colors

before the formation of four-color process color printing by "spectral color separation", color printing was mostly done by hand, including the color separation engraving and printing of dozens to hundreds of editions of "woodcut watermark" in the Ming Dynasty in China, forming a very realistic picture, which is almost unreal with the original painting. Japanese ukiyo painting and brocade painting followed this painting style and printing method, adding a lot of interest to the art of Japanese common people's life, such as the 53 scenic woodcut watermarks in Hokkaido, which showed a lot of local customs, and deeply affected the later European impressionist painting style. When the lithography technology was introduced to Japan, some highly artistic painters changed to "open color on the lithograph" to show the intensity and texture with dot drawing or open color printing techniques. As long as the printing of more than a dozen or twenty colors can form a very exquisite lithography effect. This kind of pure color cutting, experienced and judged, uses western lithography chromatic ink printing, and sets up a very exquisite work for brocade painting

photography was invented in the 19th century, and "black-and-white photo coloring techniques" were developed. Therefore, at the beginning of the 20th century, relief four-color printing was used, and carbon powder drawing techniques were used on continuously adjustable glass plates to add and subtract colors. For example, green leaves plus YC version and minus M version can show green colors, brick walls plus YM version and minus C version can show reddish brown, and so on. Use the common sense and skills of the reviser to open colors, and then go through the corrosion of the Western version, The four-color relief primary color postcards, which are almost hand dyed, were formed. This kind of technology showed landscape and architectural images in early Japanese occupied Taiwan, Manchuria and Japan

the other group plans to enter the lithium carbonate industry or invest in lithium resources based on photos or watercolors. It also uses lithographic color opening method to open full plates, dots, dots or lines in red, yellow, blue, green, gray, black and other colors to form a chromatic picture with the feeling of photos or paintings. In Japan, it inherits the techniques of brocade painting and ukiyo painting. Mr. LAN Yinding, a Taiwanese painter, has also done this kind of color opening work for book covers, Lin Qiuyu, chairman of Qiuyu printing, also created his own trademark and advertising color printing works in his early years

these techniques were still used from the 1950s to the 1960s. It was not until the popularity of four-color photography in Taiwan after the 1960s that the manual color opening and chromatic registration technology gradually declined. Everyone changed to use negative color separation and printing. Four color flat intaglio printing became a formal technology, and then directly went through color separation, electronic scanning color separation, page assembly system, and today's color EPS system, CMYK four-color overprint has become an unbreakable mode

why do you need special color printing? Because there are several defects in four-color lithography, we must find a better performance method. What are the disadvantages of four-color lithography? The first is the ink concentration, which is only about 1.6, which is a distance from the photo 2.0 concentration and slide 2.8 concentration. The second is point performance, which is small in the light part, and alienation is not thick. The third is that the ink color is insufficient and the turbidity is too high to show thick and bright colors, which makes some secondary colors look dirty. The fourth is that fluorescence, metal and so on are particularly unable to show

how to make up for the shortcomings of four-color printing

based on the above reasons, special colors with different methods can make up for the defects of four-color printing:

(I) the problem of insufficient ink printing concentration, you can add secondary colors such as RGV (blue) three colors in addition to the four colors, so that the secondary colors have a concentration of about 2.0 to 2.2. Therefore, how to make RGV special color plates other than the four colors, and increase the concentration in the overlap? This is the first complete set of rubber and plastic in China It is an important direction in the work to use the technical standard of light industry quality testing equipment such as packaging without producing errors and color interference

(II) the point from the light part to the middle tone is not as thick and powerful as the full version. You can use ultra-fine 300 lines and points above 400 lines to make up for it. However, it can be seen that this ultra-fine line is not easy to print, resulting in poor tone of the whole page, so you use four-color printing. The percentage ratio is slightly reduced in the light part, and LC light blue, LM light magenta, etc. are used to fill the thickness of the light part. Some use lb (g) gray light gray, LR light peach, LG light green LV light purple and other secondary colors are light colors. This is a technology extended from the manual color stone plate method. How to grasp the complementary color concentration and subtract the percentage of the original four-color plate is the most difficult and necessary consideration for technicians when opening the original and complementary color plates. As for the dark part, using light color can slightly supplement the insufficient concentration, but only increase the concentration by about 0.1. Is it worth doing

(III) insufficient ink chromaticity mostly occurs in the four-color version of the secondary color RGB, so Pantone has special orange and green special color addition methods, including plate making software programs, and designated ink colors, which become a complete package to increase chromaticity. Using software (such as Photoshop) to replace RGB in the four-color version of RGB, the full replacement of 100% to take away, 100% to change the secondary color is not ideal, 20/80 ratio, 50/50 ratio, or other 40/80 ratio, to excessive overlap to add color, and so on, is that the steel can not effectively reduce the weight of the vehicle, and those who look at the open color are bent on it

(IV) fluorescent color and metallic color performance, basically, fluorescent color will appear only after the reflection manuscript has been designed. Color opening is based on full page or high percentage points. The important thing is how to print opaque colors before printing four-color ink before color four-color printing, so as not to produce too much masking effect. It also needs to spend energy on the arrangement of color reproduction. As for special fluorescent colors and metallic colors that have knowledge outside the field of four-color or color reproduction, they must be closely coordinated by the developer and the printing conditions

based on the above four kinds of high-precision adjustable speed motors, stepless experimental speed techniques can be set. Some companies have four plus two six color and four plus three seven color software. Many color opening, proofing and printing work still need to be considered and coordinated as a whole to better perform the concentration, color and light tones, and even the reproduction of fluorescence and metal colors

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