Color management is essential for quality printing. Why? Because it’s the only system in place between you and your final print that controls the color accuracy of your printer. Mastering color management will save time and money in labor and materials. This article addresses the basic points of color management and the things you need to do to assure that “wysiwyg” (what you see is what you get) happens.
Color management, though technical is relatively easy once you understand its how to use the tools. For the most part, it’s not that difficult to create or select a profile that matches the output of your printer with the rich colors that you see on your screen. Photoshop CC, and other software in the Adobe Creative Cloud provide integrated color management features that can help close the gap between light and ink.
Defining Color Management
What exactly is color management? The answer lies within another question: How is the image going to be output? Color management is about manipulating the numerical color values of an image to conform to the color potential of a specific output device, weather it be a monitor or a printer. An ICC (International Color Consortium) profile defines an image’s “color space” so that it can be configured on screen to match how it will look when printed.
To match the print to the monitor’s display may at first seem daunting, but in fact, by systematically following a few steps, this goal is easily achieved
Tip 1 — Know Your Medium
Before we get into any real technicalities let’s look at the most practical aspects of color management. First of all, you’re going to have to know the capabilities of your printer. Are you printing from an inkjet printer or a laser printer, or some other device like an image-setter? What is the printer’s make and model, and what ink set does it use? Does it use four, six, eight or 12 color cartridges? Is there more than one black cartridge? Does it use pigment-based inks, water-based dye inks or aqueous-based pigment inks?
Printing ink varies from one manufacturer to another and even specific models within the same manufacturer’s product line. It is therefore important to know the specific details of your printer.
Secondly and equally essential, what substrate are you printing to? Is it glossy, matte, watercolor or some form of archival paper. Perhaps it’s canvas or even film, fabric or metal? And who makes it? Substrates vary in their ability to absorb ink. The qualities of specific surfaces will determine the look of the final print.
Tip 2 — Calibrate Your Color Window
A monitor is a window. You look within it to see the color configurations of your image. It’s essential that your monitor is displaying color at its optimal potential so that the on-screen image looks it’s best. The quick and cheap option is to use a software calibration utility. If you’re using Windows you can download and install the free Monitor Calibration Wizard from: http://www.hex2bit.com/products/product_mcw.asp.
The Mac uses the Calibrate utility found in if you choose System Preferences > Displays > Color (see Figure 1). Either of these software programs are okay for a quick observation based monitor calibration. Bit the human eye and brain are subjective.
A more accurate solution and the one that is recommended if you are working in a professional environment where calibration is critical is to use a tristimulus colorimeter that measures the temperature of the light displayed on screen (see Figure 2). The colorimeter is placed on the screen with suction cups for CRT monitors or a counter weight for LCD displays or laptops. The colorimeter measures color temperatures and feeds the values to calibration software.
There are several colorimeters on the market with software that calibrates your monitor to ensure the consistency of the color you see on screen during editing sessions. In the initial calibration screen for a print workflow I set the Gamma to 2.2, the Luminance to 90 and the white point to 5500 Kelvin (see Figure 3).
The calibration software sequentially generates images of swatches of several shades of red, green, blue, gray, and black and white. The colorimeter analyzes and feeds back to the software. The software configures the monitor profile and saves it to the appropriate folder where it is accessed when the computer is starting up. The profile adjusts the color on screen based on the measurements
Tip 3 — Know Your Color Settings
With monitor calibrated, the next step is to create a “Color Working Space” that limits the color of what you see on screen to what your printer can produce. The color range or “gamut” of potential printer colors is different than the RGB colors that your monitor can display, after all, we are comparing pigment to light.
The Color Settings dialog box in Photoshop’s, Illustrator’s, Light Room’s or InDesign’s edit menus is a good place to begin a basic understanding of color calibration. Color settings are synchronized throughout the Adobe Creative Suite so setting up a color environment in one application establishes a consistent color space for all of the software. In the Color Settings dialog box (see Figure 3) there are controls that manage all the aspects of color output and enable you to create a Color Working Space that is right for your specific printer and substrate.
Color settings are specific configurations of attributes that are applied to your image.
You can choose from a list of preconfigured settings from the Settings menu or custom settings. RGB Color Working Spaces are used for monitor displays, inkjet and laser printing. CMYK color spaces are used for files that are destined to devices that produce color separations. Under no circumstances should you convert your RGB inkjet files to CMYK color mode and apply a CMYK profile when printing to an inkjet printer even if your printer supports only four colors. Bad results are guaranteed. Click on More Options (that expands the RGB list of potential profiles). From the RGB menu and choose a profile for the printer and substrate you are using (see Figure 4).
Many printer drivers automatically load pre-made profiles into the color settings folder when installed. These profiles can be accessed from the RGB menu and were calibrated for specific printer and substrate characteristics. They modify the RGB values of the image to match the color capabilities of the ink-set and the reflective qualities of the substrate to produce an on-screen image that mimics the potential gamut of the printer’s capabilities.
Tip 4 — Embed the Profile into the Image
The working space determines current color profile. In order to see it applied to your image however you have to assign it. Go to Edit > Assign Profile (see Figure 5). Click the Working RGB radio button to assign the current working space or click the Profile radio button and choose a profile from the list. When you save the document check theEmbed Profile box in the Save As dialog box (see Figure 6). Because you’ll make separate image for each printer and substrate, be sure to label the file to indicate its profile.
Tip 5 — Know Your Policies
The items in the Color Management Policies field, program Photoshop to display warning boxes if a document has an embedded profile that does not match the current working space (see Figure 7).
I recommend that you check the Ask when Opening and Ask when Pasting check boxes for both the Profile Mismatch andMissing Profiles options in the Color Settings dialog box so that when a document is opening you’ll be informed if the embedded color space differs. Then you can choose to either convert the document to the current color space or preserve the document’s profile.
Tip 6 — Make a Custom Profile
A custom profile may be necessary if you’re using special substrates and the profile for the combination of printer and paper isn’t available. You’ll need to purchase the equipment to make a profile or you can go online and contact one of the many profile provider’s websites. Then you can load the custom profiles into the color settings dialog box.
Matching a monitor to a specific paper or printer combination is obviously a more extensive process than just choosing a profile provided by the printer’s manufacturer. You’ll need a spectrophotometer and the software to drive it. In this process you start by printing a color chart with your printer and on the specific substrate you are profiling.
The color chart consists of multiple swatches of color. You can scan the chart manually, line by line or you can purchase a scanning table which does it automatically (see Figure 8). The spectrophotometer measures the wavelength of each color swatch so the more swatches you have to work with the more accurate your profile will be. Usually the software offers three options, basic intermediate and advanced. After the swatches are scanned, the software writes a profile and places it into your Color folder in Windows or Color Sync folder in Mac to be loaded into the color settings folder and assigned to the picture.
Tip 8 — Adjust Color
There are likely to be significant color variations when you assign the color profile. Sometimes the image will become darker or contain a cyan or reddish cast. With the image visible on screen you’ll make color modifications to improve its appearance. Use your color adjustment features like Levels, Curves, Hue Saturation and Vibrance etc. to modify the image until it looks great. What you see onscreen is as close to the print that can be displayed. As you adjust color you are working within the printer’s color gamut because profile displays only colors that match the printer’s and substrate’s capabilities. So… wysiwyg!
Tip 8 — Make a Test Print
It’s not a bad idea print a smaller version or a strip of a critical portion of the image
for comparison to the onscreen image especially if you’re working with a client whose color matching is critical. You can then be assured that the colors are where they need to be before you make your final print run.
Calibration is essential to producing consistently predictable color from your printer. Since ink sets are proprietary and substrates absorb ink and produce color differently, you should create a distinct profile for each printer and each paper that you use. Predictable color means less waste in time and materials. If consistent color is important to your workflow, the initial expense of a calibration system is well worth the money in that it eliminates the extra effort and materials required to reprint unsatisfactory images.