Printing knowledge
In fact, I really want to print red red and bright, and the final method is to replace the color of the ordinary four colors with the golden color of the spot color, and then superimpose the normal 100% Y color.
We are a big printing company in Shenzhen China . We offer all book publications, hardcover book printing, papercover book printing, hardcover notebook, sprial book printing, saddle stiching book printing, booklet printing,packaging box, calendars, all kinds of PVC, product brochures, notes, Children's book, stickers, all kinds of special paper color printing products, game cardand so on.
For more information please visit
http://www.joyful-printing.com. ENG only
http://www.joyful-printing.net
http://www.joyful-printing.org
email: 860681365@qq.com
Let me talk about a simple one. How do you print black in black and bright in four-color printing? It is dark and dark.
The answer is: add 25% to 35% blue in 100% black, so the effect of printing is special black!
To print the most beautiful red, use the spot color golden light!
Turn to the knowledge about spot colors~
First, the spot color and its characteristics
Spot color ink refers to a kind of pre-mixed specific color ink, such as fluorescent yellow, pearl blue, metal gold silver ink, etc. It is not mixed by CMYK four colors, and the color registration means accurate color. It has the following four characteristics:
1, accuracy.
Each color set has its own fixed hue, so it can ensure the accuracy of the color in the printing, thus largely solving the problem of color transfer accuracy;
2. Field nature.
Spot colors generally define colors in solid colors, no matter how light this color is. Of course, it is also possible to add a spot color (Tint) to present any shades of spot colors;
3. Opacity.
The spot color ink is a covering ink which is opaque and can be covered in the field;
4, the performance color gamut is wide.
The color gamut in the set of color stocks is very wide, exceeding the RGB color gamut, not to mention the CMYK color space, so a large part of the color is not rendered with CMYK four-color printing ink.
Second, the reason for choosing the color used in color dot printing
In color dot printing, the characteristics of spot color inks are often used to select and use them. In general, it is generally used in two situations:
1. In order to print some visible light colors outside the color gamut of CMYK four-color printing ink on the printed matter.
The color gamut of CMYK four-color printing ink is obviously insufficient compared with the visible light color gamut, and the color gamut of the spot color ink is wider than the color gamut of CMYK four-color printing ink, so it can express many colors other than CMYK four-color ink;
2, to make up for the lack of printing technology.
Due to the error of each process in the printing process, equipment maintenance, working environment, human omission and mechanical wear, it is difficult to obtain a uniform and even dot color when printing small dots below 153. At this time, we can use the same color. The full version of the color (that is, the spot color field) replaces the small dots for printing, and it is easier to obtain a flat large-area color block. In addition, in order to clearly express fine graphics, such as mixed-color graphics or reverse-white lines of fine strokes, spot color processing is often used to achieve fine lines and can be expressed sufficiently and delicately.
Third, some problems should be paid attention to when using spot colors before printing
1. The unity of spot color names.
In different software, the names may vary for the exact same two sets of colors. For example, FreeHand names PANIONEI IF5 PANTIONE 1F5CVC. In this way, when the FreeHand graphic object is placed in PageMaker, the same color will have three names, and three color plates will be produced when the color separation is output, resulting in an output error. Therefore, if the data file needs to be used in more than two kinds of software, be sure to pay attention to the use of the same spot color before the integrated color separation output. The more common method is to change the name of the same spot color to a uniform name in the palette of various softwares.
2. the angle of spot color plus network.
In general, spot colors are printed in the field, and dot processing is rarely done, so the angle of spot color screening is rarely mentioned. However, when using a light colored mesh color, there will be problems in designing and modifying the screening angle of the spot color dot. If the spot color of the dot follows the overprinted area of the color printed by other dots, the angle of the spot color screening must be considered. At this time, if the angle of the screen of the spot color dot is less than 30 degrees with the angle of the other color screens, the net will produce a moiré; if the angles overlap each other, it will cause ink overprinting problems, which will cause the printed matter. Serious distortion of color. In addition, the screen angle of the spot color is generally preset to 45 degrees in the software (45 degrees are considered to be the most comfortable angle perceived by the human eye, so that the dots are arranged in an angle equal to the horizontal and vertical lines to reduce The human eye's ability to detect dots, if it is a two-tone image or a data file, there are four colors of black printing (generally in four-color screen printing, the black dot is placed at 45 degrees, the yellow is at 0 degrees, If the magenta is 15 degrees and the green is 75 degrees, if there is a spot color, or if there are more than two spot colors, it will be output at 45 degrees when the color separation is applied, so if you use the shallow mesh for the spot color, If it is possible to overprint with other screened colors, you must open the software color setting or print setting dialog box during the color separation output to modify the spot color screening angle.
3. the conversion of spot color to printing four colors.
Many designers often use some of the colors in the spot color to define colors and coloring when doing graphic design, and convert them into CMYK printing four colors when color separation. At this time, there are three points to note:
First, the color gamut of the spot color is larger than the color gamut of the printing. During the conversion process, some spot colors cannot be fidelity, and some color information will be lost.
The second is to choose the "special color conversion to four colors" option in the output, otherwise it will lead to output errors;
Third, don't assume that the CMYK color value ratio displayed next to the spot color number allows you to reproduce the spot color effect with the same CMYK component of the four-color ink (if you can use the spot color), in fact, if it is exactly the same The resulting color will have a large gap in hue.
4. Trap processing of spot colors.
Since the spot color is different from the printing four colors (printing four-color inks to create a color by mutual overprinting, that is, the ink has transparency), it is usually not used to create a color between two spot colors, which is intuitive to say that Get very dirty color effects (of course there are exceptions, such as the intention to use the spot color overprinting process in the design to produce the required, superimposed mixing of the third color, this third color is full, thick and real, such as: spot color yellow The embossed modulation of the spot color red, the two colors are overprinted to produce a stable dark red, often used as the cover of the book, etc.), so the definition of the spot color, generally does not use the overprint (OverPrint) method instead of empty ( Keepaway). In this way, when using spot colors, as long as there are other colors next to the spot color graphics, you should consider making a trapping process to prevent the occurrence of white-edge problems (the method of spot color trapping and related technical problems are more complicated, this is not Brief description).
5. Color matching system for spot colors.
When choosing a computer color matching system, first of all, it should be clear which color system is the CMYK four-color printing system, so as to know whether the color in the system you selected will have color conversion and whether it will be in the color separation output. A situation with color distortion occurs. For example, the color distribution system commonly used in graphics software includes PANTONE, TRUMATCH, FOCOLTONE, TOYO ColorFinder, ANPA-COLOR, RIC Color Guide, etc., among which TRUMATCH and FOCOL TONET ANPA COLORR are developed based on printing four colors, others All of them belong to the system of spot colors (the PANTONE system covers a wide range of colors, both print and spot colors). That is to say, in the spot color matching system such as PANTONE spot color, TOYO Color Finder and RIC Color Guide, many of them are out of the printing four-color color gamut and cannot be produced with four-color ink. The CMYK combination provided by the system. The values are also approximate. So if you choose the color in the spot color matching system and output it in four color separations; or refer to the corresponding CMYK combination values that are similarly displayed in the system, and use these values to replace the four colors with printing. The original spot color, the result will definitely lead to color distortion; Secondly, it should be understood that the spot color matching system is used for color separation processing, unless the special color is converted to CMYK four colors to output, otherwise, each used Spot colors will automatically be independently divided into a color version. By the same token, after printing the color in the four-color color matching system for coloring, the color separation output will automatically be based on the CMY ratio of the color itself to four plates, without generating more. Color version. Furthermore, it should be noted that in the dot matrix environment, the selected color (such as a spot color) is automatically converted to the same color mode as the data file to which the color is applied (such as CMYK four-color mode) after being used on the canvas. . Therefore, in dot matrix drawing software, for spot colors, it must be deliberately added or specified (for example, adding and defining spot colors in photoshop, there are two cases: if a spot color is applied as a hue to the entire image To convert the image to a two-tone mode and apply a spot color on one of the two-tone plates; if the spot color is used for a specific area of the image, you must create a spot color channel; in a vector drawing environment, When you select or define a spot color, the color will exist as a spot color attribute unless you specifically change or convert the spot color attribute to a process color (for example, a spot color added and defined in liiusttrator, even if it is referenced Other Illustrator data files or data files that will use the spot color are opened by other vector software, etc., and the color properties of this spot color are not changed).
6. the cost of spot color printing.
Generally, spot color printing is usually used for printing below three colors. If four or more colors are required for printing, CMYK four-color printing is preferred. Because CMYK four-color printing is basically overprinting with dots, and using spot colors is basically printing in the field. Although the spot color is usually used only in the image, it is customary to pay twice the price of the general ink. To estimate; in addition, if there are already four printing colors in the same layout, it will be equal to one color for printing, if the printing machine does not have excess printing units (such as less than four-color printing presses or four-color printing presses) ), it takes another time to print, and the cost is even higher.
In short, you should be careful when using spot colors, otherwise it will not only cause color distortion, but also spoil your creativity and design, but also increase economic expenses and unnecessary time waste.