18. Managing Color from Monitor to Print
What You’ll Do
Calibrate Using Hardware and Software
Change from Additive (RGB) to Subtractive (CMYK) Color
Assign a Different Profile to a Document
Convert Document Colors to Another Profile
Use Hue/Saturation for Out-Of-Gamut Colors
Use the Sponge Tool for Out-Of-Gamut Colors
Work with the Out-Of-Gamut Warning
Introduction
Color management has changed a lot in the last few years. New standards have been defined, and Adobe is at the forefront of this new technology. No longer do you have to fear color management, because Adobe Photoshop has taken all (or at least most) of the guesswork out of the equation. Adobe’s color management system (CMS), provides different rendering intents, or ways to translate color definitions between the input device and the output device using color profiles to avoid color-matching problems.
When you work on a computer monitor, you’re viewing color information in the RGB (Red, Green, and Blue), additive color space. When you move into the world of the 4-color press, you’re viewing color information in the CMYK, or subtractive color space. While a standard color press is called a 4-color press, in reality, only three colors are used—CMY (Cyan, Magenta, and Yellow—the opposites of RGB). To generate a true black, a printer must use the “K” plate (K stands for black, or key plate). Monitors display RGB colors very differently; when you factor in monitor resolutions, and the different types of monitors in the marketplace, what you see on a computer monitor is seldom what anyone else sees on their monitors. And that’s not all; everyone who owns a computer has the ability to adjust or calibrate the colors on their monitors differently, further confusing the issue.
While nothing is perfect, the world of professional printing is more controlled. For example, when you’re working on a color document that is moving to press, you can use a predetermined set of colors, such as the Pantone Matching System. The Pantone colors come printed on special card stock. When you’re looking for a specific color, you choose it from the card stock, and then that information is given to the press operator. This type of control, even including the type of paper, keeps you in charge of the process of moving from monitor to print.
Producing Consistent Color
Creating Consistent Color
You can create consistent color in Photoshop by following some basic steps:
If you are working with a production company, consult with them to make sure they provide you with any necessary software and hardware configuration and color management settings.
Calibrate and profile your monitor. See “Calibrating a Monitor” on this page.
Add color profiles to your computer for your input and output devices, such as a printer or scanner. Color profiles are typically added to your computer when you install the device. Photoshop uses the profile to help determine how the device produces color in a document.
Set up color management in Adobe programs. See “Working with Color Management” on page 472.
Preview colors using a soft proof (optional). See “Setting Up Soft-Proof Colors” on page 466.
Use color management when printing and saving files. See “Saving a Document” on page 28 and “Setting Document Print Options” on page 416.
Calibrating a Monitor (Manually)
Photoshop comes with its own color management system; however, before you can successfully use color management, you must first calibrate your monitor to a predefined standard. There are several methods available to you for monitor calibration. One is to purchase a third-party calibration system, while another is to use the operating system’s built-in color calibrator. While this section deals with manual calibration of your monitor, it is highly recommended that you purchase calibration equipment, or hire someone to calibrate your system, because the human eye is not the best device to color manage a system.
Before beginning the calibration process, let your monitor warm up for thirty minutes to an hour, and calibrate under the same lighting system that you’ll be using when you work. To manually calibrate your computer monitor, on Windows, select the Adobe Gamma utility located in the Control Panel. For Macintosh users, select the Calibrate Utility by opening System Preferences, clicking the Display icons, clicking the Color tab, and then clicking Calibrate. In the calibration application, you will be instructed to manually balance the monitor for various shades of red, green, and blue, or to pick from a set of predetermined calibration settings. Since the human eye is not the best device for adjusting color, this method produces less-than-desirable results.
Calibrating Using Hardware and Software
The digital tools available today are so sophisticated that just 10 years ago, no one would have thought them possible. Color calibration falls into three categories: Input (digital cameras, scanners), Processing (monitors), and Output (printers, presses). Each category requires calibration to create a workflow between devices. Remember a few things before you calibrate your system: Let monitors warm up for 30 minutes to an hour before doing the calibration, and calibrate the system using the same lighting levels in which you will be designing. Once the calibration of all your devices is complete, you can expect the best color consistency that technology can provide. Several companies market color calibration hardware and software; one of them is ColorCal at www.colorcal.com.
Calibrating a Monitor (Processing)
To calibrate a monitor, you will need to purchase a digital device called a colorimeter, or spectrophotometer. When you launch the calibration software, it typically displays a color target in the middle of the monitor. You would then attach the device to the monitor, directly over the color patch, and follow the step-by-step instructions. When complete, the software creates a digital color profile for the monitor and PostScript output devices use that profile to accurately print color images.
Calibrating a Scanner and Digital Camera (Input)
Calibration of a scanner and digital camera requires the scanning or photographing of a reference color target with known color values. For example, the Kodak Q-60 IT8 color target has 240 color patches, a 24-step grayscale, and reproduction of flesh tones. The calibration software reads the scanned colors and compares them to known color values to create a table of how the camera or scanner performs. Scanning a color target is easy. You lay the target on the scanner, close the lid and push the button. Digital cameras are a bit more difficult because you have to deal with the lighting conditions at the time the target was shot. With studio cameras this isn’t a problem; however, taking photographs in ambient lighting involves different times of day, sunny versus cloudy, and incandescent versus fluorescent lighting. Yet, even factoring in the potential problems, calibrating your camera goes a long way in stabilizing color information on a digital camera.
Calibrating a Printer
To calibrate a printer, you will need a digital target file. The file is sent directly to the printer. Once printed, the results are checked with a spectrophotometer, and then the software measures the colors against the target values and creates a profile. There are many variables involved in the printing process, such as the type of inks used, and the type of paper used for printing. Therefore, calibration is performed based on the fact that you will be using the same ink and paper combination, so the calibration process should be performed each time you purchase new ink cartridges and/or change the paper type.
Setting Up Soft-Proof Colors
When you work with a printer, you traditionally print a hard proof of your document, and visually preview how the colors look. Then you sign off on the proof, and the press operator begins the run. In Photoshop, you can use color profiles to soft-proof the document. Color profiles are a way to display the colors of a specific device directly on your monitor. While not as exact as a hard proof, it can go a long way to getting the colors of a CMYK document into the range of the output device. It’s important to understand that the results of the soft proof compared to a hard proof is directly dependent on the quality of your monitor and monitor profiles. When you soft-proof a document, you’re temporarily assigning a color profile to the document.
Understand How to Soft-Proof Colors
Open a document (to use soft proofing, the document does not have to be in the CMYK color mode).
Click the View menu, point to Proof Setup, and then click Custom.
Click the Custom Proof Condition list arrow, and then select from the available customized setups (check with your press operator).
Click the Device to Simulate list arrow, and then select from the available color output devices.
Select the Preserve Numbers check box to simulate how the colors will appear without conversion.
Click the Rendering Intent list arrow, (available if Preserve Numbers is unchecked), and then select from the available options to view how the colors will convert using the proof profile colors, and not the document profile.
Select the Black Point Compensation check box to map the full dynamic range of the source space (recommended).
Select the Simulate Paper Color check box to simulate the visual conditions of white paper as defined by the current profile.
Select the Simulate Black Ink check box to map the full dynamic range of black as defined by the current profile.
To save a customized profile setup, click Save.
To load a previously saved profile setup, click Load.
Check with your press operator; in many cases they have profiles set up to match the dynamic range of their presses.
Click OK.
Click the View menu, and then click Proof Colors to view the color profile for the active document.
See Also
See “Working with Rendering Intents” on page 469 for information on setting rendering intent options.
Changing from Additive (RGB) to Subtractive (CMYK) Color
RGB (Red, Green, and Blue) is defined as an additive color space, in which primary colors are added together to produce other colors. RGB is the color space of computer monitors, televisions, and most mobile devices with built-in color screens. A monitor uses pixels (small square or rectangular bricks), and each pixel mixes a combination of red, green, and blue to project a specific color to your eyes. Pixels use (on average) 24 switches to hold color information, and can produce 1 of 16,777,216 separate colors. CMYK (Cyan, Magenta, Yellow, and Black) is defined as a subtractive color space. CMYK is the color space of high-end inkjet, laser, and professional presses. A press uses plates that define each of the 4 colors; as a piece of paper passes through the press, the colors are applied from each plate. The term subtractive comes from the fact that the inks used in printing absorb or “subtract” a portion of the spectrum in order to produce other colors. Since a press cannot generate the intense saturation of an electronic pixel, the number of possible colors is reduced into the thousands. However, when used correctly, you can produce some stunning results. It’s a simple matter to convert a Photoshop document into the CMYK mode; however, good planning will ensure the colors you want will be the colors you get.
Change from RGB to CMYK Color
Open a document.
Important
You cannot convert a Bitmap or Multichannel document directly into CMYK mode. Convert a Bitmap image to Grayscale, and then to CMYK; convert a Multichannel to RGB, and then to CMYK.
Click the Image menu, point to Mode, and then click CMYK.
Photoshop converts the RGB image into CMYK.
If the RGB colors are not supported by the CMYK color space, they will be converted into the closest subtractive color values.
Working with Rendering Intents
Rendering Intents define how the selected color profile is converted from one color space into another. When you choose a rendering intent you are specifying how the colors should be displayed, even at the expense of the original gamut (range of colors) within the active document. The rendering intent you choose depends on which colors are critical in an image and on your preference of what the overall color appearance of an image should be. Many times the intent of the image’s color gamut is different than how the original image was shot.
Work with Rendering Intents
Open a document.
Click the View menu, point to Proof Setup, and then click Custom.
Click the Rendering Intent list arrow, and then select from the following options:
♦ Perceptual. Preserves the natural colors of an image, as viewed by the human eye, sometimes at the expense of the true color values. Good for photographic images.
♦ Saturation. Produces vivid colors in an image, without paying attention to the original color values of the image. Good for business graphics, and charts where you want the colors to pop.
♦ Relative Colorimetric. Shifts the color space of the document to that of the maximum highlight values of the destination. Useful for photographic images, and preserves more of the original color than Perceptual.
♦ Absolute Colorimetric. Clips any colors in the destination image that do not fall into the color gamut of the destination. Use to proof images sent to devices such as 4-color presses.
Click OK.
Printing a Hard Proof
In the language of the print world, a soft proof is viewed on a monitor, and a hard proof (sometimes referred to as a match print) is viewed on a piece of paper, typically printed on a device such as an inkjet or laser printer, that is less expensive than producing a hard proof from a printing press. In the last few years, many inkjet printers now have the resolution necessary to produce inexpensive prints that can be used as hard proofs, which previously had to be printed on high-end printing presses, or expensive high-resolution laser printers. A hard proof gives you something you can hold in your hands, and is not only useful for viewing colors, but even evaluating the layout. Since a monitor typically displays a document at a different size than your printed document dimensions, you now have an exact size to match to your final document and review before going ahead with the final printing. When you select a printer in the Photoshop Print Settings dialog box, Photoshop automatically lists the profiles installed for that printer at the top of the profile list and hides printer profiles that do not apply to your printers. If a printer-specific profile is available, Photoshop automatically selects it for the best results; however you can change it as desired.
Print a Hard Proof
Open a document.
Click the View menu, point to Proof Setup, and then click Custom.
Click the Device To Simulate list arrow, and then select a specific proof set.
Click OK.
Click the File menu, and then click Print.
See Also
See “Setting Up Soft-Proof Colors” on page 466 for information on using color profiles and setting color management options.
See “Working with Rendering Intents” on page 469 for information on setting rendering intent options.
Click the Color Management expand triangle.
Click the Color Handling list arrow, and then click Photoshop Manages Colors.
Click the Printer Profile list arrow, and then select your output device from the available options.
Click the list arrow, and then click Hard Proofing.
Click the Proof Setup list arrow, and then click Custom Setup.
Select any of the following options:
♦ Simulate Paper Color. Simulates what colors look like on the paper of the simulated device. This produces the most accurate proof; however it’s not available for all profiles.
♦ Simulate Black Ink. Simulates the brightness of dark colors for the simulated device. This produces a more accurate proof for dark colors; however it’s not available for all profiles.
Click Print.
See Also
See “Setting Document Print Options” on page 416 for information on setting general print options.
See “Changing Printer Settings” on page 425 for information on selecting Printer Settings.
Working with Color Management
Colors in an image will often look different when you view them using different monitors. They may also look very different when printed on your desktop printer or when printed on a professional printing press. If your work in Photoshop requires you to produce consistent color across different devices, managing color should be an essential part of your workflow. Photoshop gives you a group of predefined color management systems, which are designed to help you produce consistent color. These management systems are recognized by other Adobe products, and by most professional printing services. In most cases, the predefined sets are all you will need to manage color workflow or, as you become more adept at managing color, they can be used as a basis for creating your own customized sets. The power of color management lies in its ability to produce consistent colors with a system that reconciles differences between the color spaces of each device.
Work with Color Management
Open Photoshop (it is not necessary to open a document).
Click the Edit menu, and then click Color Settings.
Click the Settings list arrow, and then select from the available options:
♦ Custom. Create your own customized set (requires a good knowledge of color management and color theory).
♦ Monitor Color. For creating content for video and onscreen presentations.
♦ North America General Purpose 2 (default). For creating consistent workflow with Adobe applications used in North America.
♦ North America Newspaper. Useful for common newspaper press conditions in North America. Uses CMYK values.
♦ North America Prepress 2. The defaults for common prepress operations in the U.S.
♦ North America Web/Internet. Manages color-space content for published web documents.
♦ More Settings. Click the More Options button, and then click Settings list arrow to see more options for Japan and Europe.
Create your own customized color sets using the following options:
♦ Working Spaces: Defines the working color profiles for each color model. Working Spaces can be used for images that were not previously color-managed, or for newly created color-managed documents.
♦ Color Management Policies: Defines how the colors in a specific color model are managed. You can choose to embed or convert the selected profile, or to ignore it.
♦ Conversion Options: Defines exactly how you want the conversion process handled using a color-defined Engine, and color conversion Intent. You can adjust for black point when converting color spaces, dither color channel information when converting between color spaces and compensate for Scene-referred Profiles.
♦ Advanced Controls: Desaturate Monitor Colors gives you the ability to control the viewing of a color space on different monitors; however, if activated, images will print differently than viewed. You can also decide what Gamma level is used when blending RGB values and text.
To save color settings as a preset, click Save, and then save the file in the default location.
To load a Color Settings preset not saved in the standard location, click Load.
Click OK.
Embedding ICC Color Profiles
When you work on a color document, you’re viewing the image using your own computer, with a specific version of Photoshop, and a unique monitor calibration. What you need is a way to preserve the visual settings of the document. In other words, you want someone else to see what you see. The ICC (International Color Consortium) color profiles provide a universal way of saving (called tagging or embedding) a mathematical definition of a particular color space, and give you a reasonable certainty that the document will display correctly on other devices. Although there are several file modes that accept ICC profiles, the two most common are RGB and CMYK.
Embed ICC Color Profiles
Open a document.
Click the View menu, point to Proof Setup, and then click Custom.
Click the Device To Simulate list arrow, and then select a color profile for the image.
Click OK.
Click the File menu, and then click Save As.
Enter a file name.
Click the Format list arrow, and then select one of the following formats: Photoshop PSD, Photoshop EPS, JPEG, Photoshop PDF, Photoshop DCS, or TIFF.
Click the Save As (Win) or Where (Mac) list arrow, and then select a location in which to save the file.
Select the ICC Profile (Win) or Embed Color Profile (Mac) check box.
Click Save to save the file as a copy and embed the new profile.
Assigning a Different Profile to a Document
Photoshop’s color management system must know the color space of your document so it can decipher the meaning of the color values in the image. When assigning a profile to an image, the image will be in the color space described by the particular profile. For example, a document’s profile can be assigned by a source device, like a digital camera or a scanner, or assigned directly in Photoshop. When using the Assign Profile command, color values are mapped directly into the new profile space.
Assign or Remove a Profile
Open a document.
Click the Edit menu, and then click Assign Profile.
Select from the following options:
♦ Don’t Color Manage This Document. Select this option to remove any assigned profile (the document becomes untagged).
♦ Working RGB. Select this option to tag the document with the current working space profile.
♦ Profile. Select this option, click the list arrow, and then select a new color profile, which removes the old one.
Click OK.
See Also
See “Changing from Additive (RGB) to Subtractive (CMYK) Color” on page 468 for more information on using and working with CMYK images.
Converting Document Colors to Another Profile
There are times when you will open a document that contains an embedded profile, and you need to convert it. Photoshop gives you the option of tagging the document with another profile without converting the colors, or removing the old profile and converting the color space. Photoshop’s Convert to Profile command gives you the ability to change the profile in a document. The conversion options let you control how Photoshop handles the color changes as the profiles change from one color space to another. In addition, you may want to prepare a document for a different output destination, such as an inkjet printer or 4-color press.
Convert Document Colors to Another Profile
Open a document.
Click the Edit menu, and then click Convert to Profile.
Click the Profile list arrow, and then select a new color profile.
The document will be converted and tagged with the new color profile.
Click the Engine list arrow, and then select:
♦ Adobe (ACE). Adobe color management (default).
♦ Microsoft ICM. Windows color management.
♦ Apple CMM. Mac OS color management. (Depending on your operating system, your options may vary.)
Click the Intent list arrow, and then select an option.
See Also
See “Working with Rendering Intents” on page 451 for more information on using rendering intent options.
Select the Use Black Point Compensation check box to map the full color range of the source to the full color range of the destination profile.
Select the Use Dither check box to use with 8-bit color images; if you select this option, Photoshop dithers color pixels when converting between source and destination color profiles.
Select the Flatten Image to Preserve Appearance check box to flatten a multi-layered document.
Click OK.
Using Hue/Saturation for Out-Of-Gamut Colors
Once you’ve established that your document contains colors outside the CMYK color space, it’s up to you to decide exactly how to correct the problem. There are as many ways to correct color problems as there are tools, and each Photoshop user has their favorites. Two methods that are simple and powerful are using the Hue/Saturation Adjustment and Photoshop’s Sponge tool. Understand that the primary reason a color won’t translate correctly into the CMYK color space is due to the saturation values of the ink. A monitor can produce more saturation in a pixel than a 4-color press can produce by mixing inks.
Use the Hue/Saturation Adjustment
Open an RGB image.
Click the View menu, and then click Gamut Warning.
Photoshop displays any colors outside the CMYK gamut with a predefined color mask.
Click the Image menu, point to Adjustments, and then click Hue/Saturation.
Drag the Saturation slider to the left until all the masked areas disappear.
Record the Saturation Value used.
Click Cancel.
Click the Select menu, and then click Color Range.
Did You Know?
You can select the closest CMYK equivalent of an out-of-gamut color in the Color Picker or the Color panel. Display the Color Picker or the Color panel, select the out-of-gamut color you want to change, which displays the closest CMYK equivalent, and then click the triangle or the color patch.
Click the Select list arrow, and then click Out Of Gamut.
Click OK.
The out-of-gamut areas of the image are now selected and isolated from the rest of the image.
Click the Select menu, and then click Refine Edge.
Enter a Feather value of .5.
This softens the desaturation of the out-of-gamut areas of the image.
Click OK.
Click the Image menu, point to Adjustments, and then click Hue/Saturation.
Enter the Saturation value you recorded from step 5.
Click OK.
Press Ctrl+D (Win) or 
+D (Mac) to deselect the image areas.
The image is now ready for conversion to CMYK.
Did You Know?
Photoshop can automatically convert all out-of-gamut colors to be within the gamut area. Simply convert an RGB image to CMYK. Open an RGB image, click the Image menu, point to Mode, and then click CMYK Color.
Using the Sponge Tool for Out-Of-Gamut Colors
The Sponge tool method is a bit more work intensive; however, it gives you precise control over each out-of-gamut area of the image. Since the Sponge tool decreases saturation values from the colors based on the speed with which the tool is dragged across the image, the key to successfully using the Sponge tool to restore out-of-gamut colors is to choose a soft-edged brush, and use smooth, even strokes. Practice is the key to effective image restoration and color correction, and using a drawing tablet as opposed to a mouse will help in the control of the tool.
Use the Sponge Tool Method
Open an RGB image.
Click the View menu, and then click Gamut Warning.
Photoshop displays any color outside the CMYK gamut with a predefined color mask.
Select the Sponge tool.
Click the Brush list arrow, and then select a soft, round brush tip with a small diameter from the brush tip options.
Click the Mode list arrow, and then click Desaturate.
Enter a Flow value of 60%, and then select the Vibrance check box on the Control panel to minimize clipping of strongly saturated or desaturated colors.
Click the Select menu, and then click Color Range.
Click the Select list arrow, and then click Out Of Gamut.
Click OK.
The out-of-gamut areas of the image are now selected and isolated from the rest of the image.
Click the Select menu, and then click Refine Edge.
Enter a Feather value of .5.
This softens the desaturation of the out-of-gamut areas of the image.
Click OK.
Slowly drag the Sponge tool over an out-of-gamut area until the color mask disappears.
Continue through the document until all the areas have been corrected.
Press Ctrl+D (Win) or +D (Mac) to deselect the image areas.
The image is now ready for conversion to CMYK.
Did You Know?
You can hide selection marquees. If the selection marquee is getting in the way of seeing small out-of-gamut areas, press Ctrl+H (Win) or +H (Mac) to temporarily hide the selection marquee, and then repeat the command to restore the marquee.
Working with the Out-Of-Gamut Warning
One of the biggest problems with images displayed on a computer monitor is that they don’t accurately represent the color space of a 4-color press. There are ways that we can reduce the possibility of colors not printing correctly, but in the end the RGB and CMYK color spaces are different—in fact, they’re exactly the opposite of each other. Photoshop understands this, and gives you a way to view before printing which colors will be out of gamut. The term Gamut refers to the colors that a particular device can display or print; in the case of a 4-color press, it would describe a color that could be reproduced on that press. The out-of-gamut test is performed on an image before the conversion into the CMYK mode. Once you convert an image to CMYK it’s too late to test, because Photoshop has already made the conversion.
Work with the Out-Of-Gamut Warning
Open an RGB image.
Click the Edit (Win) or Photoshop (Mac) menu, point to Preferences, and then click Transparency & Gamut.
Select a Gamut Warning color, and then enter an Opacity percentage value (1% to 100%).
Gamut Warning refers to the color Photoshop uses to mask the out-of-gamut areas of the image.
Click OK.
Click the View menu, and then click Gamut Warning.
Photoshop displays any color outside the CMYK gamut with a predefined color mask.
Did You Know?
There are other ways to identify out-of-gamut colors. In the Info panel, when you point to an out-of-gamut color, an exclamation point appears. In the Color Picker and the Color panel, an alert triangle appears.