If we compare the printing industry of Vietnam now with a few decades ago, we can see a clear improvement. The modernization of industries including the printing industry has kept our print management and printing workers up to the level of the printing industry in the world.
Remembering in the 80s, Chinese paintings were flooded with northern provinces, Thai paintings were abundant in the southern provinces, especially cafes, restaurants, and houses were hung in three plates. People including printing techniques are not beautiful. Many of our provinces were worse than the anti-French and American resistance wars in the forest.
At that time, it was only near the Lunar New Year when manufacturers and companies were excited about colorful pictures. In the normal days, if the covers of magazines and newspapers are printed in different colors, they are considered as “used”.
At present, printing pictures with many colors, every printer can print. The printing enterprises of the Ministry, Thanh, District, District and many printing houses of the Province, some have 2 or 4 color printers and printing businesses with only one color printer also print very nice types of publications. There are inferior to each other in productivity, but the quality of the product is not inferior to how far, because the publishing and printing materials are the same.
However, in terms of ink theory, about the color and the order of the ink stack, when printing multi-colored pictures of printers in many places is limited, there is a lack of basic reasoning to explain when printing is good and bad. clear persuasion.
The printing enterprises have 4-color printers (wet printing), enough measurement tools, the printer works in a comfortable, comfortable cold room that can be adjusted immediately when the color of each color is printed. It’s not like the pattern.
But in printing factories that do not have a one-color printer but print multi-color images (wet and dry), without pre-printing and climateizing printing paper, the printing is not easy like the sample. If the printer’s printing press is a non-skilled enterprise, it is very fluttering, not knowing where the printed calendars look like.
The printing of multi-colored picture overlapping tram, which color first and which color, the printer is each way. Roll offset printing at a newspaper printing factory still found it unstable. One day I took the newspaper to see, I saw pictures of beautiful colors, suitable for nature very familiar eyes. But there are also days when we read the newspaper and saw the image of yellow people like turmeric, or red like tomatoes, suddenly we felt uncomfortable eyes. However, the newspaper readers do not care much about the image quality because most of the print job is also too short, the price is low, the newspaper is printed on one side is not smooth, not white to mimic.
As for the offset sheet printer, the order of the stacked inks is not the same, the reason and experience have its own use and do not dare to claim to be the best method. is better then (want to determine exactly to open the new contest clearly).
However, printers that use single-color machines to print multi-colored photos also have their own way that is not mentioned in the book.
The story is as follows:
In 1955, I followed the order of printing a stacked color of a printer at the Fine Arts Printing Workshop (Beijing) .When they printed large art pictures, it was important not to try the printing (due to time limitation). classify:
First type: portrait photo (leader photo)
The most difficult is to print so that the right skin color, because it takes up a large area on the image. The basic color of the face is red (lotus leaf M). Complementary for red is yellow. Therefore, the overlay order is Red (M), Yellow (Y), Blue (C), Black (K). Red printed in advance for the same color as the skin, yellow printed after for supplement can be bold, light, thick, thin, backward, easy to adjust, print the right color on the face that has been successful to 90% accuracy color. Also blue, black in the light very little, heavy on dark areas, backdrops, extra positions, if there is a little wrong, little attention to the viewer.
In the 1960s, many offset printing workers at the Hanoi Offset Printing Factory often exchanged with each other, making it difficult to print the leader image. Because the masses are well aware of the skin color as well as the characteristics of the leader, if they print only a little bit, they immediately recognize it. That’s how it is hard to print portrait photos, leader photos
The second type: Landscape photos.
There are usually clouds, trees, rivers, mountains. If you print Cyan (green) first, keep the ink in the sky, the base color when there is yellow Y supporting the second printing, there will be green (green) in the field, the forest is easy. Increase or decrease the color for the sample.
Therefore, the order of printing overlapping ink colors in the landscape of CYAN, YELLOW, MAGENTA, BLACK. Red, black after printing is effective in dark, stone, earth colors, if there is a slight color difference with the landscape, the viewer Few findings are easy to ignore.
Sometimes the sample image is both portrait and landscape, the printer needs to understand the subject of the sample image and see the area of the person and the scene somewhat to pay attention to the technical outsourcing of the printed image is vivid and close. closer.
The third type: Still lifes
Sometimes it’s a house machine, a house, a statue, a bronze drum, a warm eel skin color, a machine … The printer sees whether the basic or mixed colors take up a lot of the image area to determine the ink color when printing, right know basic colors, complementary colors, contrast colors to print closely to the sample.
A body of moss, blue and yellow is the basis of fresh green, black is complementary to green, making the color darker green, redû is the most contrast in bright spots, if excess printing will fall Purple is not the same as camera body. Therefore, depending on the sample code, you can print in order: GREEN, RED, YELLOW, BLACK or RED, YELLOW, BLACK, GREEN.
When printing a photo of a bell or a bronze drum, looking at the pattern gives us the feeling of a dark green, blue and black light. A magnifying glass on the print board shows the same print area, the 90% dot area is the same, the two colors are 300 degrees apart, but because of the wet print, the blue prints in the end, to create blue light On the dark areas of the brass drum or bell, you can add varnish to the blue ink to make the details easier to float.
One more thing is as follows:
In 1982, I worked with a Chinese printer friend at the 4 th Public Private Business Printing Enterprise (now in No. 7). This friend is also a decent worker, the disciples often respect. But when you see multi-color photo prints, you only print the formula GREEN, YELLOW, RED, BLACK.
I have met many times, talked to him but he paid little attention to change, maybe due to habit, afraid to improve. By Tet that year, when printing a magazine cover of Long An Pedagogy College, the cover image of a girl’s face accounted for 70-80% of the printed area, she printed GREEN, YELLOW, until RED printing, even though there was so thick and so thick that there is still redundancy and lack of red. (Because in yellow eyes it is also difficult to distinguish the intensity of light sometimes have to bring out the sun, or make clear blue glass). By the time printing in all colors, the girl’s face was yellow and malaria-like.
Although the printing did not reach, it was supposed to be reprinted, but due to the Tet holiday, it still had to be cut and closed, and back then it was “subsidized”, even though they complained, they still paid enough money for the factory.
After this, the other printer experienced me and gradually changed the way and often talked with everyone about the printing technique and clearly see: If printing portrait photos in one-color printer, red printing will hold tightly parked the correct color on the face. Then add gold to complement the skin color, the location of the image is highly appreciated, if the main position is damaged, the beard position if printed is beautiful, no one will notice. The value of the printed picture is completely damaged!
The above example, if you are using a four-color printer, there may be nothing to read. But with “olden days” or colleagues who are currently using a one-color printer to print multicolor pictures with tram, may have picked up some useful experience in this article.
Source Nguyen Hoan