What is CMYK?

Dec. 14, 2022

      What is CMYK? Today, RX packaging will give you a detailed introduction:

      CMYK is a color mode used for printed matter that relies on reflection. How do we read the content of newspapers? It is the sunlight or light that shines on the newspaper and then reflects it into our eyes to see the content. It requires an external light source, and you can't read a newspaper if you're in a dark room.


      As long as the image displayed on the screen is expressed in RGB mode. As long as the image seen on the printed matter is expressed in CMYK mode. For example, periodicals, magazines, newspapers, posters, etc. are all printed, so they are in CMYK mode.

      1. CMYK—that is, the four colors of cyan, magenta (magenta), yellow, and black. In printing, these four colors can usually reproduce thousands of other colors;

      2. Spot color - spot color ink refers to a pre-mixed specific color ink (or special pre-mixed ink), which is used to replace or supplement the printing color (CMYK) ink, such as bright orange, green, fluorescent color, metal gold and silver ink, etc., or it can be bronzing plate, embossed plate, etc., or it can be used as a partial varnish plate, etc. It is not made by mixing CMYK four colors. Each spot color requires a special printing plate when it is printed. (It can be simply understood as a pair of spot color film, and the spot color is printed separately when printing), spot color means accurate color.

      Attachment: spot color - refers to the color that is not synthesized by printing CMYK four colors during printing, but is printed with a specific ink.

      3. Why does CMYK add black? The three colors of cyan, magenta and yellow are also the three primary colors of printing. In theory, the three colors can be mixed to produce black, but in reality, due to the limitation of production technology, the purity of ink is often not satisfactory, and the mixed black is not strong enough, so we can only rely on purified Black is mixed. In addition, ink consumption can also be saved. If there is no black ink in the black part of a picture, the same amount of CMY is mixed into black. If there is black, you can directly use black to reduce the amount of ink used.

      The CMYK model is aimed at printing media, that is, based on the light absorption/reflection characteristics of the ink, the color that the eye sees is actually the color of the object absorbing a specific frequency of light in white light and reflecting the rest of the light.

      Values from 0 to 100% are available for each CMYK quad-color ink. Specify a lower percentage of the process ink color for the brightest color and a higher percentage for the darker color. For example, a bright red might contain 2% cyan, 93% magenta, 90% yellow, and 0% black.

      The color picker in PS-RGB (additive color) and CMY (subtractive color) are complementary colors.


      RGB is added with black as the background color, that is, RGB is 0 for black, and 255 for white.

      CMY takes white as the background color, that is, CMY is 0 for white, and 100% for black (but in practice, due to the purity of ink and other issues, pure black cannot be obtained, so K is introduced).