For example, if we're testing a Canon printer, we print on 4' x 6' Canon Photo Paper Glossy. We print the Granger chart and the Parrots picture on a 4' x 6' sheet of standard glossy photo paper matching the printer's manufacturer.

We then send the document to the printer via WLAN (wireless LAN) to print. The printer settings we use are as follows:

We connect the printer via Wi-Fi to the same wireless network as our test computer. The Parrots picture provides a more realistic representation of the printer's performance when printing a photo. 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. This zig-zag line roughly denotes the most-saturated tint of that particular hue. The characteristic that sets it apart is the presence of a bright zig-zag line across all the colors at various heights. 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. To evaluate a printer's color gamut, we use the 'Parrots' picture as a sample and the Granger chart (sometimes referred to as the 'Granger rainbow').

Printer ink test image