Is color separation technology no longer needed

At present, many CMYK files received by printing companies are directly printed on the plates for printing. The printed results are less than the customer's color drafts, or the colors and levels of the pictures are not good. The biggest reason is that the customers come to the file. "Color separation" was caused by improper handling. There are two common examples. First, the total amount of ink in the cmyk file is too large, because some software sets the total amount of ink in the color to be 400%. When printing, there is an excessive amount of ink in the same position, causing the ink to dry too slowly. There is a phenomenon of bottoming and dragging. However, printing on uncoater paper, which is commonly known as book paper, is not only difficult due to the thick ink, but also results in deep-spaced webs being lumped together and unclear. The second example is that in the production process, designers rely on the effects printed by the printer. When they print out dark and color cast, they have to modify the file until they print a satisfactory color draft, but the file's cmyk value is fundamental. Not suitable for printing. The example I have seen is that the value in a certain position in the file is 8%, but the customer provided the chromaticity measurement on the same position to get 24% shades of light, if you know how to print friends will realize that 8% of the outlets are too small, How can I print 24% shades of light under normal printing conditions?

The above situation has revolutionized the prepress technology since the 1985 Apple desktop computer desktop desktop publishing revolution. Prepress processes in the past include art design, image processing, and typesetting. And color separation can be completed in a desktop computer. To make past professional processes easy by using computers and software, many professional jobs fall into the hands of non-professionals. Designers must take a number of positions to understand typing, image processing, color separation, etc. Work, but do they have enough expertise? In addition, the industry of planting and color separation will gradually be eliminated!

The author asked about "color separation" in the teaching of color management and related courses. Most of the students said that they didn't know it. When asked by friends in the printing industry, many people thought that the work of "color separation" was no longer necessary. Again. In recent years, friends who have joined the company have not known about the “color separation” work. For some days in the industry, there is no need for “color separation” because there is no film and film for photography.

In many people's minds, "color separation" refers to affixing the manuscript to the glass platen of the electronic color separation machine. After the manuscript is scanned and color separation is calculated, the four-color film with dots is directly output, which is called "separation." The interpretation of "color separation" has been different in its realization. The original is attached to the glass of the scanner and passes through the pmt-photo-multiplier tube or charge-coupled device (ccd-charge) of the scanner. - Coupling device converts the color and light/dark information on the original into an electronic message, which becomes the pixel of the image. It is called "scanning". The scanned rgb image is converted into a cmyk image by the icc profile or color setting. This process is called “color separation”.

Will complete the cmyk file output film or plate, this is called "output" ("output"), so "sweep", "separation", "output" of the three steps add up to the definition of past "separation" .

Because of the popularity of desktop computers and software, many people can easily accomplish "color separation." But what is the setting behind the process of converting rgb to cmyk? Most people say that they do not know, then the cmyk files that are separated out are colored. It is not known whether it is suitable for actual printing conditions.

To understand the role of color separation, we begin with the principle of color reproduction. In the traditional film photographic color transparent film is the use of rgb color filter, the image was recorded on the cmy three-layer color film, the color film on the cmy three-layer color is subtractive principle of the principle of different colors.

The transparent sheet is attached to the glass of the scanner to get the rgb image message, and the rgb value is converted into the rgb working color space, such as adobergb or srgb, by the scanner icc profile or the scan color setting. Digital photography captures the image from rgb's ccd and converts it into the rgb working color space through the icc profile of the digital camera. The srgb is used in small digital cameras, while the professional digital camera uses adobergb.

When the image is stored in rgb mode, it can be converted to cmyk mode through appropriate software. The most popular software is adobe photoshop, and there are other software such as binuscan's cmyk production+ and photo retouch pro, aurelon's iciss, alwan. The company's cmyk optimizer and most output rip color conversion functions.

Although there is the help of color separation software, the operator must also understand the printing and color separation technology, such as what is the standard printing density, dot gain, trap rate, and printing contrast; color separation, such as color correction, Gray balance, tonal range, color relative shadow, black version, gcr, ucr, and total ink amount, etc., can be used to understand the use of software functions to separate good image files and print ideal color effects.

In 1976, when I was admitted to the Kwun Tong Institute of Technology in 1976, I gave a fake photogravure course. I learned the traditional color separation and platemaking techniques. By the lens filter color separation, horizontal screen version of the Internet, straight-type amplifier direct separation of the Internet and other technologies, to learn the last year to operate the electronic color separation machine. At that time, color separation technology apprenticeships took 3 to 5 years to complete. There is no "separation" project in the current design and printing courses, and there is no apprenticeship training in the industry of "Separation". It is believed that the technology for the separation will soon be lost. Therefore, the education sector should set up appropriate separation courses. , and the industry should also retain the positions of color separation technicians.