Color models CMYK and RGB when printing

When preparing a print template , there are many points to which attention should be paid: design, type of paper or foil to be printed, choice of printing house, possible costs... There is one more point that is very important and should not be missed may – color models. The basic color models are RGB and CMYK , which render colors differently. In this article we explain what these abbreviations mean and how they differ.

What is a color model?

The color model is a method of describing a color using quantity characteristics. Color model is a term denoting an abstract model of describing color vision as three or four numbers. These numbers are called the color component (or color coordinates). The color model is used for the interpretation of the radiating and reflecting colors. The color plural number of the color model thus determines a color space .

Color space RGB

RGB is the abbreviation of three color names Red, green , and blue , on which the RGB color space is based. This is an additive color space , ie all possible colors (around 16.7 million shades) are created by additively mixing these three primary colors in different proportions. When red, green and blue are 100%, white is produced, black is produced when all colors are absent.

If the blue color is added to the green, turquoise ( cyan ) is formed, blue with red gives crimson ( magenta ), the addition of green to red creates yellow ( yellow ). The RGB color space is used for the visual transfer of data in the digital world: on computer and television screens, in both modern and old cameras, scanners, etc. RGB offers the widest range of colors. This is the main reason it is considered the default color mode for most computer programs and apps. Most programs for photo editing, such as Adobe Photoshop, also use RGB as the standard setting.

If you create an image in digital format or digital design, you don't have to think about the color mode, because the colors look almost the same on all screens: they all transmit colors in the RGB color space. However, if the template is printed on paper or acrylic glass, this mode is not suitable.

CMYK color model

At the heart of the color model are three colors that result from mixing two primary colors (red+green, green+blue, blue+red). The abbreviation is made up of the first letters of the English names of these colors: cyan , magenta and yellow – CMY . These are subtractive colors , when mixing these colors in a proportion of 100%, black is formed, the absence of colors - white. CMYK is used in polygraphy for standard printing and is therefore the technically required color model . Paper and other print materials are white/light and reflect the colors. To get black, turquoise, magenta and yellow would have to be mixed together, which wets the paper very much. Black color was then added to this color model to avoid overmoistening during printing. Black is called “ Key Color” in English and gives the fourth letter to the color model – CMYK .

Differences between RGB and CMYK

So, it was stated above that RGB and CMYK are diametrically opposed:

✔

RGB is a color model used to create colors on the screen, based on adding colors and encompassing around 16.7 million shades of color.

✔

CMYK is a color model with/after which the image for printing – artwork – is formed (prepared), which is based on color subtraction and cannot reproduce all color shades.

The basic difference is as follows: when you combine all RGB colors (red, green, blue) in equal proportions, you get white, which is the purest combination. The RGB color is actually an emanating color (or light). In the CMYK color model, all colors are subtractive and therefore the more colors mixed together, the darker the final color will be. CMYK color is a reflective color (i.e. printing color).

Sign printing: with RGB or CMYK?

From the basic difference it follows clearly that a CMYK color is not the same as its "corresponding" RGB color . This moment should not be forgotten when printing the door sign, as the door signs are printed on the basis of the digital print template. The template prepared in RGB color mode must be converted to CMYK colors. It is possible, for example, with the computer programs Adobe Photoshop or Adobe Illustrator. In the case of the colors that show large deviations, you have to manually select the most precise adjustments possible in CMYK mode.

Bulk printing is done in CMYK mode these days. Printing with RGB color space is not yet possible in large quantities: it requires a black printing surface, the introduction of white color into printers and is very expensive.