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In a perfect world, all monitors would show colors in exactly the same way and all printers would print out the image exactly as it appears on the monitor.
This just doesn't happen.
The first task for the printmaker is to ensure that the computer knows how his or her monitor displays colors -- what sort of bias does the monitor have,
does it shift colors to red, for example. I first create a monitor profile
which loads up when the computer starts and shifts the color display to compensate for the monitor bias. A colorimeter is attached to the screen to
periodically calibrate the monitor and update the profile. If this is done correctly, I know that I am seeing on the screen and registering in my brain what the computer is registering in its
brain.
The next requirement is to see what bias the printer has. I now make a printer profile -- not just one for the printer alone, I make one for each combination of printer, ink and paper. I use the same ink with the same
printer all the time, but I use four different papers -- hence four profiles. To create one, I print out an image which is comprised of a series of colored
squares. These squares have a digital signature, a numeric color value which is known to the computer (the values are built into the image file.) A
spectrophotometer assesses the printed image and determines the difference in the color values between the intended colored squares and the resulting printed colored squares. The computer now knows what biases the
printer/ink/paper combination has -- do the colors shift to blue, for example.
When I print the image, I impose the printer profile on my image file which subtly alters the colors to compensate for how the printer will interpret the
colors. If all goes well, then, the image printed will be the same as the image on the screen.
If all goes well..... In reality, as I have discovered, the profiling is a good
starting point, but it is not always wholly accurate. I find that with most images, adjustments of tone and contrast have to be made and with some
images, particularly those with highly saturated but quite different colors, tricky changes have to be made. If I decide a printed green is too yellowy
and correct it, I have also altered the oranges and made them too red. Balancing these hues is rather like one man trying to balance a see-saw. "Rio
Grande Valley 2" is a case in point. To achieve a good print I had to select individual areas of the image and shift the color within that area to ensure a
print match. I now have two finished files for the same image -- one which is correct on the screen and one which looks wrong on the screen but is used to print the image so it matches the first one on the screen.
Apart from the need to match the print to the monitor image, there is a second necessity: I have to ensure consistency, print after print. Each of my
images is offered in an edition of 50 prints. Number 50 must look like number 1. This process of profiling ensures consistent results. The whole procedure recounted here is known as "color management."
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