Gravure plate color correction (below)

2. Handle the color of the two dot skip areas (1) Handle the color of the 80% dot skip zone. According to the rule of engraved gravure cylinder dot and OPP film proofing and printing dot enlargement, as the tone is deepened, there is a simultaneous change in the size of the dot and the depth of the cell hole, and the dot gain increases linearly, and the darker tone increases. The bigger the more, the more urgency, the 80% area is a jumping area where the network turns, more than 80% of the outlets increase in a straight line, and the color hierarchy is easy to merge; the outlets below 80% are more moderate, and generally can be printed at a level. . Therefore, if you want to hire color processing methods, you should open the distance between the deepest basic red color and the complex color of orange, red, brown, etc. that are in the depth range of 80%-85%, preferably 20%-25%. , that is, 100% of the red field, the dark red, net, brown and other complex colors dropped to less than 80% to avoid 80% of this network jump area, this can ensure proofing, printing, printing, full of red In the field, on the other hand, it is possible to make the dark red, net, brown, and other complex colors in the dark tone not be red and achieve the best of both worlds.
(2) Handle the color of the 5% dot jump area. According to the rule that the engraved cylinder is easy to lose small dots and the OPT film is proofed due to high light modulation and ink transfer, the small dot transferability of the printing is poor, and 5% or less of the dots cannot be printed, which affects the color amount of Gaoguangjiang tones and is easy Partially merged with the extremely high-gloss network. Therefore, it is necessary to consciously deepen the adjustment of the basic color of high light modulation, such as the M version of the pink, C version of the light blue, light green, Y version of the light yellow, etc., should be deeper than the required color amount 3% -5% , to make it away from the extremely high light, to achieve a full-bright tone color full.
3, emphasizes the brightness of the degree of color Packaging products more emphasis on the visual effects of color, requires bright colors. Therefore, for the originals of fruits, seeds, etc., in vivid colors and bright colors, they should be composed of primary colors and inter-colors as much as possible, and the complementary colors (opposite colors) should be used appropriately or not, so that the colors are bright and bright. Such as orange orange, the bright tone, bright tone of the opposite color C version should be 0%, so that bright orange eye-catching. If you put a little C color, orange is gray.
4. The tones of all objects in the continuous transition tone of the physical color are composed of three major faces and five tones. The three major surfaces of fruit, seeds and other photographic works are bright, medium and dark. Five different light and dark shades are the highlight color, the intrinsic color, the middle color, the shadow color and the reflective color. Continuous transition. Therefore, when performing color correction and adjustment, attention should be paid not only to the change in the shade between shades, but also to the importance of maintaining border transitions between dark and medium tones, and highlights and bright tones. Note that in many products, the hue is hard to disjoint, and the particles are rough. The main manifestation is that the hue in the 80% dot area jumps deeper, and it is disjointed from the hue of the light tone area, and a hard rough mouth appears. Therefore, when coloring and adjusting colors such as oranges, tomatoes, vegetables, cowpeas, etc., it is necessary to connect the shades to the natural, especially the scenery version, such as the warm-colored M version, the cold-colored version C, to maintain a continuous transitional tone.
5. Handling the color of foreign disks Now that the gravure plate manuscripts have undergone great changes, more than 60% are foreign disks, that is, electronic documents designed by advertising companies. Since the image scanning separation adopts the long-order black edition of OCR process color separation mode, and the gravure printing process of packaging products adopts the short-step black edition process mainly consisting of three primary colors, therefore, the OCR color of my industry The data is adjusted to the three primary color-based color data, which brings great difficulties to the gravure platemaking. The external disk masters three adjustment methods:
(1) Decrease the amount of black color of the darkened image and make it away from the black characters outside the image. Use the SELECTIVE COLOR selection tool of PHOTOSHOP to select the BLACK color and convert the color of the black version from 95% to 1000. The percentage is reduced to about 70%; the C version is increased from about 60% to 90%-93%, and the M, Y version is increased from about 55% to 80%-83%.
To shorten the tone of the black version, use the CURVE curve tool to shorten the highlight point starting point to about 40% of the C version.
(2) Use the CURVE curve tool to moderately darken the complementary colors in the color. Since the GCR process replaces the complementary colors in the colors with black, the levels in the colors will be affected after reducing the color and reducing the tone of the black version. Therefore, some compensation should be made.
(3) Deepen the insufficiency of the dark original color caused by the dark substitute color. For example, the three primary color dots of the dark and dark parts of the red apple are M90%, Y83%, and C25%. After the GCR separation pattern is described, 25% of the black color replaces the complementary color C25%, and the primary colors M and Y25% are also lowered. The first method is to use the lasso tool to draw out the dark part of the apple, blur the edge, and then deepen it with the CURVE curve tool. The second is to use the magic wand tool to deepen the effect of increasing the darkness of the dark red apple.
6, color adjustment notes (1) color adjustment to be carried out after the level and correct color cast, because the gray balance of the level curve and correct color cast will affect the color change, which is often not noticed.
(2) The color corrections are related to each other. When using the color correction tools such as PHOTOSHOP to adjust the color adjustment, the amount of color correction cannot be too large, and the amount of color correction is too large to cause a series of problems. Such as:
A. It will affect the colors in the vicinity and cause confusion. As a result, the postal issue is often unable to correctly analyze and determine the problem.
For example, if the M version adds excessive amounts of red, it will cause excessive M color in purple blue and brown; if the Y version adds excessive yellow color, it will cause excessive redness in the large red and green Y colors. Therefore, do not patronize the correction of a local hue and forget about the color changes that are related to each other. If you do not want to influence, you should check out the big red and yellow colors separately.
B. It will affect the level and level of the basic color with large saturation.
(3) PHOTOSHOP color correction tool HUE/SATURATION, COLOR BALANCE, SELECTIVE COLOR is mainly used for the adjustment of the primary color (primary color), the inter-color (secondary color) color portion, do not use it to correct the complex color (third color). The CURVE level curve is mainly used for the adjustment of the gray, the complex color and the overall color density to deepen and reduce the color misalignment, and does not use it to adjust the color, the properties of the two are different, and the adjustment focuses are also different.