Colors of our everyday life (part 2)


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Incoming and reflected light

Colors of objects, living beings, etc. differ from the colors we see e.g. on a home TV screen or smartphone. The former are reflected from the pigmented surface, while the latter radiate directly into our eye. These are quite different principles. The first consists of three colors: red, blue and yellow. By mixing all these colors we achieve all the other shades and using all the colors at once results in black because the pigments have soaked up the whole spectrum and there is no reflected light coming into our eye. Everyone has encountered this as a child when painting with tempera paints

In contrast, in the case of incident light, the rule of RGB space applies – there all shades are achieved with the intensity of red, green and blue. Using all colors evenly, however, results in white light. For example, if you take a magnifying glass and bring it closer to the WHITE screen (TV, computer, phone, ..) you will notice clusters of red, blue and green pixels that work from afar – white. The intensity of each pixel, however, determines the final color we perceive with our eyes and brain.

Colors and shades in print

Even in print reproductions, we would like to achieve an economically viable system for simulating the entire color palette – that is, by mixing some basic colors. So we use dots of different colors that reflect light into our eye, and if they are small enough, the eye combines them into a “third” color, just like on the screen. For the needs of process printing (most printed materials, magazines, brochures, books…) they developed the CMYK standard – Cyan (blue), Magenta (red-pink), Yellow (yellow) and K (black). The latter is intended for additional contrast and blackness, which cannot be achieved just by mixing CMY.

All other shades are simulated by the size of these dots arranged in a grid. You can also easily see this with the help of a magnifying glass, which you bring closer to a printed multicolored publication. The system is fairly simple and allows for quick and relatively inexpensive reproduction. As a result, it is by far the most widely used standard worldwide.

Unfortunately, using this system in some situations does not give us ideal results. Above all, some very vivid colors are truncated, such as light green and especially orange (we do not have these problems with the incident light emitted by the screen). Where the demand for the most faithful reproduction is very high, in addition to CMYK, additional colors can be used, which complicates and increases the cost of printing, and in addition, such printing also requires special machines.

The perception of printed color is, of course, greatly influenced by the material on which we print. The color must be as white as possible for good reproduction, and the structure of the material is also important. Matte surfaces will give us a more muted and less contrasting image than smooth and shiny ones.