If you need to use a printer for color-critical work like printing professional-grade photos, posters, or logos, you'll likely need a model with good color accuracy and a wide color gamut. Color accuracy and color gamut are two different measures that relate how well a printer can produce colors; while color accuracy measures the difference between the final color output and the original, intended color, the color gamut relates the range of colors the printer can produce. Having a printer with a wide color gamut is important if you want to accurately reproduce a variety of colors that would otherwise be very difficult to reproduce using a lower-quality printer.
This article discusses our methodology when scoring only the color gamut of a printer. For more information about how we test color accuracy, see our Color Accuracy test article.
The color gamut of a printer matters if you want to print smooth color gradients and seamless transitions between different colors. A printer's color gamut is just as important as its color accuracy if you want to accurately reproduce very specific colors, like very light tints, very dark shades, or very vibrant hues. Doing so may be difficult for lower-end printers that have worse print quality or use lower-quality ink.
We use a Granger chart (shown above, sometimes referred to as the "Granger rainbow") to test the range of colors a printer can produce. Like HSL charts found in many digital art programs for precise color-picking, the Granger chart is a picture that displays a very wide array of colors, organized by the color's hue from left to right and how light or dark the color is from top to bottom. The characteristic that sets it apart, however, is the presence of a bright zig-zag line across all the colors at various heights. This zig-zag line roughly denotes the most-saturated tint of that particular hue. The presence or absence of this zig-zag line in a display or printed image is a tell-tale sign of how wide a printer's color gamut is.
We connect the printer via Wi-Fi to the same wireless network as our test computer. The printer settings we use are as follows:
We then send the document to the printer via WLAN (wireless LAN) to print.
We print the Granger chart on a 4" x 6" sheet of standard glossy photo paper matching the printer's manufacturer. For example, if we're testing a Canon printer, we print on 4" x 6" Canon Photo Paper Glossy. If the manufacturer doesn't have any dedicated photo paper, we use generic-brand, standard-gloss photo paper. Otherwise, if the printer doesn't support either photo paper or 4" x 6" sheets, we print on generic-brand, Letter-size plain paper, with the Granger chart printed in a 4" x 6" format in the middle.
We then use the Epson Perfection V600 scanner to scan the printed Granger chart and use the scanned file as a preview. We compare the actual print-out itself against the original when scoring the printer's color gamut.
Certain aspects we look out for include:
Above are examples of printers with outstanding, decent, and mediocre color gamuts. You can click on the images for a better-quality view. Notice that for the imagePROGRAF (9.0), the zig-zag line already gets lost between the red and pink, and the colors aren't as bright as the original, but there isn't any banding between colors. For the PIXMA (7.0), the zig-zag line is lost in all but a few colors, the dark bottom should extend further up, and there's some banding between colors. Finally, for the LaserJet (6.0), the zig-zag line is also lost in all but a few colors, but the colors don't fade gradually to white or black at the top or bottom, and there's lots of banding between colors.
Black and white printers are always scored at a zero, regardless of how well they can reproduce monochrome tints or shades.
If you need a printer that can produce a wide variety of colors, we advise that you opt for a photo printer with extra dedicated photo cartridges. Although color printers with a single tri-color cartridge or three dedicated cyan, magenta, and yellow cartridges are fine for everyday prints, more involved applications like professional color reproduction or photo printing require more specialized color cartridges like photo black or photo blue cartridges. These extra cartridges allow for a wider color gamut, as certain colors can't properly be reproduced by mixing cyan, magenta, and yellow. For example, blue hues might look too purple, while composite blacks might be slightly tinted cyan or red.
However, if you already have a printer and want to maximize its color gamut, you should use dedicated photo paper to ensure colors are rendered as brightly as intended. Even better, we recommend that you buy branded photo paper that matches the manufacturer of the printer you're using, like Canon Photo Paper Plus Glossy II for a Canon printer. You'll also want to ensure that the print settings match as closely as possible to the type of paper you're using to print; for example, "Media Type" should be set to "Photo Paper Plus Glossy II" in this case. This ensures that the printer's color intensity and ink output matches the media being used.
For more advanced settings in ensuring a wider color gamut and more accurate colors, the process tends to be very involved and depends on which application you're printing from. The most common method involves allowing the application you're printing from—rather than the printer or the driver—to control color management using a special profile designed for a specific printer model and media type. For example, if you're using Adobe Photoshop, you need to go into the printing menu, select "Photoshop Manages Colors", and select the printer ICC profile that matches with the printer model and media type you're using. These ICC profiles are generally included when installing the driver or software package that comes with your printer.
Ultimately, it's important to ensure that your print settings match with the media type you're using each time you print.
A printer's color gamut conveys the range of colors it can produce and is different from its color accuracy. Having a wide gamut is important if you want to print a wide range of colors or produce smooth color gradients without any banding. We use a Granger chart to judge how wide a printer's color gamut is and score the printed output by how well it matches colors and prints gradients between hues, tints, and shades. Although some printers may score rather low, many of them will still perform more than well enough for casual prints. As a result, the color gamut of a printer is much more important if you're an enthusiast or professional engaging in color-critical work.