Many have heard the abbreviation CMYK, which is used in the printing industry, but do not know how it is decrypted. To understand what four colors indicate these letters and what properties this autotype is possessed, our article will help.
In the world of optical illusions
Before figuring out what CMYK is, you need to understand the nature of such a miracle as natural light. Few people think that colors exist only inside the system, the necessary components of which are the audience, lighting and the subject. The optical wonders do not end there. For example, although we perceive pure white light as colorless, it contains all the colors of the spectrum visible to the human eye. It is his multicomponent that gives the objects a coloring. When white light reaches an object, its surface, regardless of its properties, absorbs specific colors. At the same time, the rest are reflected and create the perception of the image in the viewer, which will be faded or bright.
Reproduction of text and images on physical media in terms of human perception
The paper on which printing is most often performed is initially white and has the ability to reflect the entire spectrum of colors of sunlight that falls on it. The better its quality, the higher the reflective properties of the surface. At the same time, a dye is a substance that absorbs a certain color. If he delays the rays of all lengths, except those that correspond to the red component of the spectrum, then in sunlight a person sees only such a dye. If we look at the same pigment in the rays from the blue lamp, it will seem black to us.
When various dyes are applied to white paper, the number of reflected colors is reduced. For example, by applying blue pigment to the paper, we create a situation where it does not absorb only it.
There are combinations of colors, when mixed, you can get a paint that can completely absorb all the rays reflected by the paper, that is, make it black. In particular, for this it is enough to apply the same amount of purple, cyan and yellow pigments.
It should be noted that such a color model does not need white paint, since this is the color of the paper itself. In those areas of the image where it is needed, no pigments are simply applied, leaving the surface clean.
Subtractive model
Paper and other printed materials are surfaces that can reflect natural or artificial light. Obviously, it is more convenient to calculate how much of it in the form of rays has changed its direction to the opposite than how much it has been absorbed. Thus, if you subtract 3 primary colors from white, that is, the basic components of RGB, you get a triple of additional CMY colors .
Why "K" and not "B"
Usually for those who do not know what CMYK is, this abbreviation is puzzling. After all, as already mentioned, this color model uses 4 different pigments. Three of them are named after their first letter. In addition, black color is used. One version claims that K is an abbreviation for the English word black. It was used instead of “B” to denote a black film in the printing industry, so as not to be confused with the same letter from the RGB model (English blue). The fact is that professional color correctors manipulate with 10 channels RGB_CMYK_Lab and use all available color spaces. Thus, when applying the abbreviation for four-color autotype, the phrase “action with channel B” would require clarification about which of the models in question, which would be inconvenient.
There is another opinion. According to this version, “K” is an abbreviation for the word “key,” that is, key plate. They designate a printing form for black ink, which is used on top of the already applied three previous pigment.
In addition, some experts are inclined to believe that “K” has a German pronunciation and means the word kontur. In favor of the latest version is the fact that traditionally the black film in the printing business is called contour.
How to pronounce in Russian
Although the CMYK color model has been used for a long time, many to this day do not know how this abbreviation sounds right. Specialists advise pronouncing it out loud, like "Cm-Wye-Kay." In addition, there are recommendations to call the 4-color avotype “si-poppy”, as well as use the term “full color” or “process colors”.
RGB, CMYK: what is the difference
If the CMYK scheme is used in printing, the red-green-blue model is used when displayed on televisions, monitors and other displays. As known? they consist of pixels, which are small dots, each of which has 3 backlights and, depending on the brightness of each, glows with the desired shade of the given color.
When printing an image from a computer, the printer or offset machine does this using CMYK inks (cyan, magenta, yellow, key color). In this regard, viewing the image in the RGB scheme may differ significantly from what you get on paper or other physical media.
The reason is the method of transferring the image from one color scheme to another, which simply cannot provide a one hundred percent hit. Indeed, many RGB shades simply do not exist and cannot be implemented in the CMYK palette (which colors are the main ones in this system, you already know). They are replaced by the closest shades, however, the differences still turn out to be quite noticeable even for the naked eye.
Why are there 4 colors in the CMYK model, and only 3 are used in RGB
As you know, black paint can be obtained by mixing purple, yellow and blue, taken in equal proportions. However, for a number of reasons it is necessary to use additional pigment. There are several reasons why four-color autotype is black. Among them:
- a mixture of yellow, purple and cyan pigments in practice creates a dirty brown paint ;
- process colors do not provide saturation and shade stability of gray areas of the image;
- when displaying very small black details of a text or picture without the use of such a pigment, the risk of insufficiently accurate coincidence of the application points of cyan, magenta and yellow shades increases;
- black pigment (usually ordinary carbon black) is much cheaper than other paints;
- mixing 100% yellow, magenta, or cyan pigment at one point in the case of inkjet printing sufficiently wetts the paper, deforms it, and increases the time required for drying.
Problems of the latter type arise in the process of offset printing. Also, depending on the device? there is a certain limit on the amount of paints. For some printers, it can even be quite large and reach 260-280%. This means that “true” black color on such printing devices cannot be obtained by mixing pigments. Therefore, another black paint is used.
What is CMYK printing
When printing on an offset or silk-screen printing press, a color laser printer, etc., it is possible at each point to either use a layer of ink of a specific thickness, or to leave the substrate clean and untouched. Thus, for halftone transmission, the image is rasterized. In other words, it is represented as a combination of points of four colors. The density of their placement determines the percentage of use of each of the paints. At a distance from the physical medium (paper, film, etc.), points that are close to each other merge, and the human eye sees the necessary shade. Rasterization happens:
- amplitude, when the number of points is constant, but their size varies;
- stochastic when there is no regular structure of points;
- frequency, assuming size preservation with a changing number of points.
How not to be disappointed when printing photos on a printer
Today printers are in many apartments. They are used for preparing homework, writing term papers, essays, etc. Very often, they also try to print photographs on the printer. However, as a rule, such attempts end in disappointment, since a bright picture on the screen turns into a faded copy on paper. It's all about translating the image from the RGB model to the CMYK model.
To see how the photo will look on paper, you can use the program Adobe Photoshop. In this case, you can edit the image in order to get the best result.
Now you know what CMYK is, how this abbreviation is deciphered, and what its disadvantages are. Most likely, in the near future it will be replaced by a more advanced color rendering scheme, which will increase the print quality of images.