Monday, January 31, 2011

The Myth of the Screen to Print Match

By Rich Seiling

One of the biggest misconceptions in color management is the belief that you calibrate your monitor and printer to match each other.

If you think that’s how it works, you’re not alone. And that belief will cause you problems and frustration at one point or another, if it hasn’t already.

Want to break through the misconception and learn how it really works? It’s not hard, it just requires a little under the hood knowledge of color management.

Let’s start with an example from music. Consider this: If a guitarist and a cellist were playing the same piece of music, would you expect the guitar to sound like the cello? No. We all know that the character of instruments is different, even if they are playing the same notes, so we don’t expect them to be the same. This is also how we should think (though, to a lesser degree) about monitors and prints.

The problem with the idea of making your monitor and printer “match” is that it forgets about the file itself…and the fact that the file is the most accurate representation of color.

Files, by their nature, are what contain the colors we want to reproduce. They are the most accurate representation, even though they record color in a numeric form our eyes can’t see. To see the colors, we need output devices, monitors and printers, which convert those numbers into a visual representation. To understand how they work together, we need to understand how colors are stored and translated.

Files contain the formula to actual colors, not just a vague definition of a color. A pixel value of 211R 0G 0B doesn’t just mean the 231st step of red above zero. It means a very specific color, as plotted in the spectrum as defined by a specific ICC profile.

The problem with monitors and printers is that they are each limited in the colors they can reproduce. This is constrained by things like gamuts (the range of colors they can create) and white points. When we measure and define the colors a device can produce, we have its colorspace, which can be described in a ICC profile.

The file almost always has more colors than the devices we use to display color. The way color management works is it uses these ICC profiles which describe a device’s colorspace to map the colors from the file’s colorspace into the device’s colorspace as accurately as possible.

Why? Well, you can’t just feed a pixel value of 211R 0G 0B from the file into a printer or monitor and expect to get the right color red. In all likelihood, you’ll need to feed in an entirely different combination of RGB values to the output device in order to get the same exact color as defined by 211R 0G 0B in the file. The color profile contains the information that lets the computer translate color from one colorspace to another.

This is the important point. Color management IS NOT trying to make the monitor match the printer. Instead, it’s trying to make each device, independently of any other device, represent the file as accurately as it can, within its own limitations. The file is always the starting point; monitors and printers are just representations of the file.

The reason we see a “match” between profiled monitors and printers is this: When we make each device represent color as accurately as possible, if the two devices are similar enough, then those two devices often display the color in a similar manner…so similar that we can say we have a “match.”

This is what leads to the idea of the “match,” and that idea causes many photographers great frustration. When one of the devices is more accurate than the other (usually the print, because a good print is more accurate than any monitor), then the photographer sees a difference between the two, and no longer thinks they are “matching.” The usual response is to think something has gone wrong, because they are expecting a match.

Instead, the photographer should understand what color management does, and conclude that they are seeing the limitations of the device. You have to realize that devices like monitors do not represent the print 100% of the time so you can shatter the myth of the match.

Now, I’m not recommending you throw away your color-accurate monitor, but to understand and work with its limitations. A true color-accurate monitor that has been accurately profiled can produce an extremely good “match” to a print for a wide variety of photographic applications. But when it doesn’t, we should look at the print (printed with a proven ICC profile) as the most accurate representation. One would not expect a student violin to sound like a Stradivarius, would they? So, while our monitor may be good for many performances, we’ll need to pull out the Stradivarius (the print) for our most breathtaking music.

Color Management is called “management” not “matching” for a reason, and now you know why!

Rich Seiling is a photographer and the owner of West Coast Imaging. You can read more of his articles at

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