Ingeniously arrange four-color printing color sequence from different printing factors
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: info@joyful-printing.net
Multi-color printing has now dominated the printing industry. How do we arrange the printing color sequence when we use a four-color printing machine for production? The author combines his own practical experience and summarizes as follows.
1, ink factors
The four-color machine generally uses a printing color sequence in which the thickness of the ink film is gradually increased. For example, the C ink density is 1.6, the ink film thickness on the paper is about 0.85 μm, the M ink density is 1.4, the ink film thickness is about 0.9 μm, the Y ink density is 1.0, and the ink film thickness is about 1.3 μm. If printing in the color sequence of C-M-Y, the overprinting effect is good. If the printing color sequence is changed to C-Y-M, the thickness of the ink film is 0.85 μm, 1.3 μm, and 0.9 μm, respectively, resulting in poor overprinting effect of M color. Although the thickness of the ink film can be increased by increasing the amount of M ink to improve the overprinting effect, after the thickness of the ink film exceeds 1.2 μm, the dot size is increased to cause color shift.
When the density of the C ink is 1.6, the thickness of the ink film is 0.85 μm. If the density is reduced to 1.5, the thickness of the ink film is about 0.7 μm. This is the lowest value of the ink that can cover the paper when printing on the coated paper, below which the density value is lower. Printing will be poor on the ground. Therefore, in the case of such a problem, it is preferable to dilute the ink so that the thickness of the printing ink film reaches 0.7 μm or more. Of course, when the thickness of the ink film exceeds 1.4 μm, in addition to the increase in the dot size, defects such as back smearing or reverse overprinting are likely to occur. It can be seen that the ink density is very important, and it is necessary to fully understand the relationship between the thickness of the ink film and the ink density during printing.
Four-color printing is a wet-wet overprinting, and the post-printing color is easy to be anti-sticky. Therefore, from the viewpoint of the viscosity of the ink, it is preferable to perform printing in accordance with the order of decreasing ink viscosity. In addition, in terms of the transparency of the ink, the printing color sequence with increasing transparency is preferred.
If the four-color printing is based on the K version, the background color removal is deeper. From the perspective of reverse overprinting, the best printing color sequence is C-M-Y-K. However, if the K version is a complementary color version, the printing color sequence can be selected K-C-M-Y, which can save costs from another point of view. However, if the K version is over-inked, it will cause the ink coloring phenomenon in the latter color printing, which must be noticed.
2, product features
There are many varieties of color printing, each with its own characteristics. Therefore, we must arrange the printing color sequence according to the characteristics of the product itself.
For newspaper printing, the color report is printed on newsprint paper that is porous, easy to deform, and low in whiteness. It is difficult to overprint on a high-speed rotary offset press, and the color reproduction ability is worse than that of offset paper and coated paper. The national standard "Quality Requirements and Inspection Methods for Newspaper Prints" stipulates that the printing quality of color pictures is basically in line with natural color, and the four-color overprinting is accurate. Therefore, the printing color sequence of the color newspaper, in addition to considering the overprinting effect of the ink, also meets the requirements for overprinting and color reproduction of the color picture of the newspaper in the national standard. For example, the newspaper “Zhoukou Daily”, which was printed by our newspaper, has one of the most popular pictures. Therefore, after comprehensive consideration of various factors, we adopted the printing color sequence of C-M-Y-K, which not only ensures good overprinting effect, but also does not produce cross-stitching phenomenon in high-speed printing state.
When copying prints or high-end artwork, it should be printed in strict accordance with the color sequence of the original to better faithfully copy the original. When printing a ticket, you should first print the shading and then print the border. When printing certain printed products, the main text or picture should be kept clear and not covered by other ink colors. Therefore, the main color sequence of the main body or the picture should be used.
3, overprint accuracy
During the printing process, through the rolling of the drum and the action of the fountain solution, a certain degree of deformation and extension will occur, which will inevitably affect the overprinting accuracy of the printed product. From the accuracy of overprinting, how should we choose the printing color sequence to better ensure the registration of printed products?
First of all, the ink color with low precision requirement should be printed first, and the ink color with high precision after printing should be printed, so that the paper will gradually stabilize after the first two colors are printed, which can reduce the inaccuracy of post-printing. Secondly, the color version or the dark version with a smaller area should be printed first, and then the color version or the light color version with a larger area should be printed, so that even if the paper has a certain degree of deformation at the beginning, it has less influence on the overprint of the printed product.
The color sequence arrangement of four-color printing should be analyzed in detail, and the printing color sequence should be adjusted at any time according to the actual situation to achieve the best combination of printing quality, printing cost and printing operation.