| C | Cyan (Turquoise) |
| M | Magenta (Hot pink) |
| Y | Yellow |
| R | Red |
| G | Green |
| B | Blue |
| K | Black |
| C | = C |
| C + M = | B |
| M = | M |
| M + Y | = R |
| Y = | Y |
| C + Y | = G |
| C + M + Y | = K (Proceed Black) |
OK, now what to do about Orange, Purple, Brown, and all those colors in between?
The only way to accomplish this, is to mix a variety of the base colors in different quantities, plus use the white of the paper.
So, an orange, for instance, is going to be a mixture of magenta and yellow, with more yellow dots than magenta ones. And a purple is cyan and magenta with either more magenta for a red-purple, or more cyan, for a bluer purple. Most browns are made by differing amounts of all three (C, M and Y). The main purpose of the true black ink is to add contrast. and darken the process black which tends to be muddy. It can also save ink, since one drop of black can substitute for a drop of all three.
Ah, suddenly we see that to create one pixel representation on paper, we need quite a few drops, like maybe 12 or 16.
Printers with more ink colors, or variations of droplet size and ink densities need less dots to create the same amount of colors. However, if the printer is fast enough and the dots small enough, the effect can look quite similar with just the 3 colors plus black ink. Even so, most inkjet printers probably cannot produce more than about 64,000 colors. However, our eyes don't really distinguish the 16 million a monitor can theoretically produce. That's in part why we can get away with using Jpeg Compression on a photographic image and not notice the losses.
Back to printers: When a printer states it can offer 1200, or 2400 or even 5600 dpi, that doesn't mean that every dot is created. In fact, if every drop was, the paper would be saturated with ink, since the dots are not small enough to fit. Instead, dots are laid down in a manner to represent a color pixel. The number used by inkjet companies is the number of addressable locations. This may take the head going over an area several times to create that many locations.
Truthfully, most people see little different at viewing distance between a print printed at 5600 as one printed about 1200 dpi. But the printers can truly address those locations, however, rarely, if ever will they be addresses right next to one another, instead dots are moved to make as accurate a dot pattern as possible.
The best inkjet printers formulate their dot pattern positions at about 1400 dpi, however, in terms of how our eyes operate, this translates to at best a 400 dpi full color image, which is about equal to a well made custom 4" x 6" color print made using wet photographic techniques from a 35mm neg. Most "drugstore" prints are about half that.
With proper use of unsharp masking and other techniques, an quality inkjet printer can surpass a wet photography print, equating similar source image size.
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