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By John Woram
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Go to the Amazonian Jungle
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All Charged Up
Color doesn't travel well. This is a phenomenon you'll notice when you try to get a color printout of an image to look the way it did on your monitor. The printed page usually appears as a pale (or worse) replica of what you see on screen. And that raises an interesting question: If the displayed page and the printed page don't match, what's causing the problem? The monitor? The printer? The paper?
Chances are, it's all of the above. And that prompts a more difficult question: How do you adjust a color printer? You probably won't find any color correction controls on your monitor's front panel. Although you can spend hours tweaking your display, the net effect on the printer is still zero. The finer points of color matching didn't concern the average user back when the price of a decent color printer was sky-high. But since color printing is within almost anyone's financial reach today, it's worth spending a bit of tweaking time to get the best results possible with your system.
Your first visual reference point is the monitor, so make sure it looks its best. Some models have a push-button or slide switch unobtrusively located at the rear of the monitor, where it is easy to overlook. Depending on the specific monitor, it may be labeled as signal level or input voltage (usually 0.7 or 1.0 volts). Try each setting. If the difference is obvious, then of course use the one that delivers the best results. Otherwise, set the switch for 0.7 volts, which is the best match for most video adapters. You may see a slight change in brightness as you adjust the switch setting.
Alternatively, the switch settings may be labeled as 75 ohms and high impedance. Use the 75-ohm position, unless a second monitor is linked to the first or the video adapter output is less than 0.5 volts peak-to-peak. If there's any doubt, the 75-ohm position is preferred. Again, the visual difference on screen may be slight.
The next step is obvious in concept, if not in realization: Set the brightness and contrast controls to their optimum position. If you're really serious about optimizing your system, get a video utility like Sonera Technologies' DisplayMate (800-932-6323, 908-747-6886), and walk the many steps through the optimization maze. If you insist on doing it yourself, open a DOS box, set it for full screen, run a directory listing and increase brightness until the black background turns dark gray. Then back off until it goes to black again. Remember that focus is often inversely related to brightness. If the image isn't sharp enough to suit you, make sure the brightness control is not set too high.
Next, adjust the contrast as desired. As a double-check, open any Windows word processor and select the Wingdings font. Type a string of the lowercase letter "u," which should appear as black diamond characters. Then go to Format/Font to change the color of some characters to dark gray and others to light gray. The on-screen difference should be obvious. If not, tweak the contrast control until it is.
Once the screen display is as good as it gets, it's time to tweak the printer. Here's where Windows 95 comes in handy. Its ICM (image color matching) system, licensed from Eastman Kodak, writes a set of monitor profiles into the C:\Windows\System\Color folder. The ICM file takes the monitor's display characteristics into account, and tailors the output signal sent to the printer so that hard-copy colors will agree with those seen on the screen.
The general procedure is no trivial task. To open an obvious paintcan of worms: As intensity is increased, a mix of equal parts red, green and blue goes from black to white on screen. The same combination goes from white to black on paper-at least in theory.
In practice, the printed black may take on a brownish tinge. Accordingly, many color printers use CMYK (cyan, magenta, yellow, black) instead of RGB (red, green, blue) inks. The separate black ink supply allows the printer to print black as black, rather than as a potentially muddy combination of the other three inks.
To determine if ICM is enabled for your monitor, run the Registry Editor (Start/Run/Regedit) and open the HKEY_LOCAL_MACHINE key. Toggle down to the subkey called SOFTWARE\Microsoft\Windows\CurrentVersion\ICM\mntr\none. The Name column in its Contents pane should list nine monitor profilexx entries (where xx is 00 through 08). The accompanying Data column lists the ICM file associated with each profile. If ICM is enabled, the following information appears on line 2, immediately below the usual (Default) (value not set) line at the top of most Contents panes: default "profilexx".
If this line does not appear, the system does not currently use an ICM profile. But if it's there, note the appropriate profilexx entry for the filename associated with that profile number, then use Explorer to find the file in the Windows\
System\Color folder. Highlight that filename and click on the right mouse button to view the Context menu. There should be a check mark next to the Set as Default option at the top of the menu. Or as an alternative, highlight each ICM file, one at a time, and note the one whose Set as Default option is checked.
Double-check the ICM profile, since Windows 95 doesn't always select the proper profile, or may select none at all. Contact your monitor manufacturer to find out which ICM profile should be enabled if you're not sure which one it should be. Then use Explorer to set that profile as the default. To choose another profile, select it and again use the Context menu's Set as Default option.
By the way, you can't clear the current profile simply by re-clicking its Set as Default option. Instead, you have to click once on the Uninstall option, reopen the Context menu and select Install in Place. This sequence leaves the ICM file in place, but clears the default check box.
To determine if your color printer's driver also supports image color matching, look for a prtr (printer) subkey under the ICM key. If it exists, look for a subkey under it that specifies a color printer. A final subkey should specify the name of the printer color profile, which will be used if that printer is set as the default. That file will likewise be found in the Windows\System\Color folder.
As you choose settings for your printer driver, Windows 95 will select the appropriate .ICM file. Or, if you're in the mood to experiment, you can try setting various .ICM files as your default.
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Hewlett Packard's HPSCAL.INI
Not all color printer drivers support the ICM system. Hewlett-Packard's own driver for the newer models 1600C and 1600CM supports a proprietary Color-Smart system instead of ICM. As a further consideration, the Registry's DefaultDevMode entry for an HP 1600C printer shows "(zero-length binary value)" in the Data column, and the relevant configuration data is stored instead in an [HP DeskJet 1600C ColorSmart, LPT1] section of WIN.INI. Furthermore, various user-selected configuration changes are written into an HPSCAL.INI file in the C:\Windows folder. These inconsistencies don't have any performance implications, but they do suggest that the .INI file will be with us for at least the immediate future.
Assuming ICM is supported, highlight the desired color printer icon, click the right mouse button and select Properties. Select the Graphics tab and click on the radio button next to Choose Image Color Matching Method to open the Image Color Matching sheet. You should see the following options listed:
(The nomenclature may vary, depending on which printer you're using.)
To realize just a little more ICM power, many monitors are now bundled with Sonnetech's Colorific (800-847-0725, 415-957-9941) software utility, which provides even more control over color matching, and may also reveal printer limitations that would not otherwise be discovered. For example, Windows 95 supports three color-matching configurations-saturation, contrast and colormetric, optimized for business graphics, photo reproduction and Pantone color matching, respectively. But if you experiment with all three, you may not find any difference among them, simply because the current printer profile doesn't support all three configurations.
The Colorific calibration procedure also gives you some insight into how an ICM profile is configured, as boxes of various shades of red, green and blue are displayed against backgrounds of the same color. Select the shade that best blends into the background and perform a few other calibration procedures. The customized color profile modifies the output to the printer to create a closer match to the on-screen image.
Spend some time calibrating your system, and you'll be able to send your color print jobs on their merry way-and they'll be in much better shape when they finally reach their destination.
Senior Contributing Editor John Woram is the author of Windows Configuration Handbook (Random House, 1993). Contact John in the "Optimizing Windows" topic of the WINDOWS Magazine areas on America Online and CompuServe.Click Here to find the e-mail IDs for our editors, who can put you in touch with this author.
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