| In recent years the price of home and home-office | | | | yellow and black inks that are capable of a wider color |
| inkjet printers has declined dramatically. Unfortunately, | | | | gamut, and are different from the standardized CMYK |
| the typical home user’s knowledge of color theory, | | | | inks used in commercial printing. This means that they |
| color “spaces” and inkjet operation has not | | | | are CMYK output devices, despite the fact that |
| improved as much as the technology has, leading to | | | | printing from a computer means they have to handle |
| continuing confusion about such things as “RGB,” | | | | the RGB color space also. |
| “CMYK” and other such formerly arcane terms. | | | | Going both ways |
| A little remedial training in color theory is indicated. | | | | Some early inkjets (such as some HP Photosmart |
| The first thing most people learn (usually in grade | | | | printers) were originally RGB output devices with those |
| school) about color is that there are three | | | | three ink colors, but most of today’s printers are |
| “primary” ones. But even this is a controversial | | | | CMYK output devices. However, unless you are |
| area, as scientists describe the three as red, green | | | | converting your color spaces in Photoshop, you are |
| and blue while art teachers call the primary colors blue, | | | | most likely sending RGB information from your |
| red and yellow. It is through combining these colors in | | | | computer to your inkjet. |
| various amounts that the full “gamut” of | | | | This means that the inkjet printers are generally set up |
| human-perceivable color can be created. For simplicity, | | | | to prefer RGB input that is then translated to the |
| the former is normally called the “RGB” color | | | | specific printer's CMYK color space by some sort of |
| model and the latter “primary colors.” | | | | “proprietary conversion” that takes place at the |
| Computers are confusing, too | | | | “driver” stage. That is, when the print job is |
| The advent of the Information (Computer and Internet) | | | | handled in the computer, the drivers (specific or |
| Age has not helped clear up the confusion. The fact is, | | | | generic) for that printer will do the color space |
| computer monitors operate on the RGB model, making | | | | conversion “on the fly” so that you don’t |
| the monitors themselves an “RGB color space.” | | | | have to. |
| But other technologies and processes use yet a third | | | | Summing up, then, the vast majority of today’s |
| color model to create all the hues, the main one being | | | | consumer inkjet printers are four-color (CMYK |
| the CMYK (Cyan, Magenta, Yellow, blacK) model used | | | | process) printing devices, but they prefer RGB input |
| in printing. | | | | and can create more (and more brilliant) colors, across |
| Putting colors onto a readable surface (paper mostly) | | | | a wider gamut, than any other process currently in use. |
| results in our reading off of reflective surfaces, bringing | | | | Amazing machinery |
| yet another variable into the color creation process. | | | | Today’s computers, graphics software, monitors |
| Over time it was discovered that breaking colors | | | | and inkjet printers perform a very complex task. As a |
| down into CMYK components resulted in the best | | | | “color production system,” together they create, |
| approximation of human-perceivable colors, and that is | | | | mix and print virtually all the colors under the sun by |
| the process used by color printers (on what are called | | | | combining the four CMYK inks. Some pretty heady, |
| “four-color” printing presses). | | | | complicated science is involved in calculating how |
| Printing at home | | | | much of the various inks are required for what colors, |
| Home printers, however, cannot possibly operate like | | | | how the ink drops are applied to the paper and what |
| complex four-color presses, in which the paper is | | | | size the drops should be. |
| “hit” with four different printing plates carrying | | | | This is some impressive work going on. Remember, |
| varying amounts of cyan, magenta, yellow and black | | | | the computer and printer driver are working together |
| inks. When combined in certain amounts, and at certain | | | | to calculate all of the color conversion, and all of this is |
| angles and resolutions, most colors are well replicated. | | | | taking place while the print head is moving horizontally |
| However, the CMYK model has trouble with metallic | | | | and the paper is moving vertically through the printer, at |
| and bright colors, which has led to the development of | | | | minute and precise intervals. The slightest error in math |
| five- and six-color presses – CMYK plus the | | | | or movement, then, will result in wrong colors and |
| needed fifth and/or sixth color. | | | | spoiled prints. |
| Inkjet printers for the home are Desktop inkjet printers | | | | This article is the merest of introductions to a |
| are CMYK (hardware) devices. That is, the vast | | | | fascinating and complex world, involving physiology, |
| majority of them use four inks (Cyan, Magenta, Yellow, | | | | light, optics, computers and printing technology. You |
| Black). It is important to remember that the goal of the | | | | could make a career of studying any one of these |
| consumer inkjet printer is not to replicate what comes | | | | topics, but the makers of inkjet printers for the home |
| off a commercial CMYK press, but to give consumers | | | | have to coordinate research and development while |
| what they are accustomed to seeing in color | | | | considering all of these variables. If color theory |
| photographic prints. | | | | intrigues you, continue to read up on it and don’t |
| Therefore, the various manufacturers of such devices | | | | forget to balance the art with the science to get the |
| – Hewlett-Packard, Epson, Canon, Brother and | | | | complete picture. |
| dozens more – develop their own cyan, magenta, | | | | |
