CMYK is a practical application of the CMY colour model in which black is used alongside the three primary colours (cyan, magenta and yellow) to enable digital printers to produce darker and denser tones.
- CMYK refers to the four inks or inked plates used in colour printing: cyan, magenta, yellow, and black. Black is often referred to as the ‘key’ colour because it is used to enhance the depth and detail of the printed image.
- The CMYK model works by overlaying colours that partially or entirely mask the background colour which is usually white paper. The inks reduce the amount of light that would otherwise be reflected, thereby creating the desired colours through the absorption of specific wavelengths.
- CMY and CMYK are called subtractive colour models because the inks “subtract” the colours red, green and blue from white light. In essence, the inks absorb certain wavelengths of light and reflect others, which combine to produce the perceived colours.
- When an observer looks at an image printed using CMYK inks on paper, they see the light that has first passed through the inks to the paper, been reflected off the paper surface, passed through the layers of ink again, and then reached the observer’s eyes. This interaction of light with the ink and paper creates the final visual image.
- This means that:
- When incident light contains all the wavelengths of the visible spectrum (white light) is reflected from areas of paper that have no ink on them an observer sees white highlights in an image.
- When white light is reflected from areas of an image that have cyan ink on them the observer sees red.
- When white light is reflected from areas of an image that have magenta ink on them the observer sees green.
- When white light is reflected from areas of an image that have yellow ink on them the observer sees blue.
- Where different amounts of cyan, magenta, and yellow overlap, they create other colours by subtracting some wavelengths of light but allowing others through.
References
- CMYK is a practical application of the CMY colour model in which black is used alongside the three primary colours (cyan, magenta and yellow) to enable digital printers to produce darker and denser tones.
- CMYK refers to the four inks or inked plates used in some colour printing. The four inks are cyan, magenta, yellow, and ‘key’ (black).
- The CMYK model works by overlaying colours that partially or entirely mask the background colour (usually white). The ink reduces the light that would otherwise be reflected.
- CMY and CMYK are called subtractive colour models because the inks “subtract” the colours red, green and blue from white light.
- Remember that when an observer looks at an image printed using CMYK inks, they are looking at the light that has first fallen on and then been reflected off the surface they have been applied to.