In a previous article I jokingly mentioned that for a "professional DTP graphic designer" RGB is like asking a new trainee in the department - not really serious and professional. Well, of course, this situation is overcolored, but indeed the conflict on the CMYK - RGB line exists. So let's clarify how these two gentlemen differ, why one is considered a greater professional and what will happen to them next... although I'm a lousy fortune teller.
Let's start with the obvious
RGB is a color model derived from the physical perception of visible light - so here we have three components (Red, Green, Blue) representing the most basic (generic - for programmers) colors. Each of the components of this color can take the value 0-255 thus giving 16.7 million combinations. This model is the so-called additive model - in short, the values of 0 for each component will give us the color black, the maximum - white.
CMYK will therefore be slightly different - it is not based on the physical perception of light, but on printing pigments (Cyan, Magenta, Yellow, blacK) being thus much more adapted for printing. Its components take values of 0-100 giving fewer combinations than RGB, but allowing to obtain "better" yellows and blues ("cleaner, fuller colors"). It is a subtractive model - contrary to RGB, the values 0 0 0 0 give the color white, while the four "hundreds" result in black.
Why popularity in printing
After all, it's not like someone once said that this is the way it is and that's the end of it... In addition to the reason I mentioned above, CMYK is also a relatively simple and conflict-free translation to the popular Pantone, which cannot be said about RGB. Another reason is related to the ease of printing - since the CMYK components correspond to popular printing pigments it is easier to prepare colors using this system. Due to the lack of need for translation, these colors are also as expected (that is, comparing the CMYK color on a professional monitor with the printout, we will get an identical image, in the case of RGB the image will be different). Finally - the printing technique - due to its characteristics, printing using CMYK is done by overlapping successive component layers - without mixing inks.
The ideal system?
Not really... Apart from the fact that almost no one has a professional calibrated CMYK display at home, so almost no one is able to properly visualize such colors the problem for printers has become the printing method itself. In order to guarantee the previously described lack of mixing of colors, it is necessary to print the color in the so-called raster - if we want to print semi-transparent yellow we do not dilute the yellow to half saturation, but print it in the form of a "checkerboard" (specifically, in the form of dots whose distribution reflects the saturation of the color - we can achieve this, for example, by controlling the spread of equally sized dots [stochastic] or controlling the size of the dots [amplitude], although de facto they do not have to be dots). Also important is the way of combining patterns - these need to be applied at the right angle to avoid the moiré effect (Moire striations) - the optical overlapping of dots resulting in more pronounced color bars in the image.
How about RGB after all?
After all, it reflects visible light better, is more "natural" and has more color combinations... Reasoning right - and it has found its outlet, but not quite. RGB is experiencing its second youth appearing more and more as a complement to CMYK colors in the color profiles of newer equipment. However, this solution is relatively unpopular, expensive and limited to only certain printing methods, but it gives the best results combining the precision of CMYK with the richness of RGB colors. However, RGB alone is not doomed either - as it is often used in so-called digital printing methods.
Who won?
None. Although a kind of "rivalry" between the two models is often emphasized, in fact the two have coexisted for years, adhering to the principle: RGB - display, CMYK - print. Thus, users of all kinds of electronics can enjoy vivid colors, while users of graphics can enjoy color accuracy and "purity" of colors and compatibility of the print with the design, even in the case of Pantone printing. Only graphic designers condemned to operate between both spaces are at a loss, often cursing their variety 🙂
