Because different printer, ink, and paper/media combinations reproduce the values in an image in different ranges, it is critical to adjust your image value range to align with the specific combination you are using. One of the most important steps in this process is to set the white point (the first visible tone of ink that shows a difference from the paper). Setting the white point accomplishes two objectives; it begins the process of neutralizing the color in the image and aligns the highlight values the printer can reproduce with the tonal values in your image file.
Setting the White Point Target Values
Double click the White Point Eyedropper (highlight target) Tool.
White Point Color Picker
This will bring up the Color Picker. You will actually be setting the white point target values in this case, not selecting a foreground or background color.
Enter the appropriate RGB values for the printer/media combination you are using. To determine the appropriate settings utilize the Tone System White Point Parameters Chart. Visually check to determine where you want the white point to appear. Remember, the RGB settings should be the same value. If you have not tested the white point parameters of your printer/media combination, you can use R247. G247. B247 as a general starting point for a high quality Ink-Jet printer.
White Point Target
The White Point Target pictured at left is used to determine the white point setting for specific printer and paper combinations.