Adobe Photoshop CS2 On Demand [Electronic resources]

Using the Hue/Saturation for Out-Of-Gamut Colors

Once you've established 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 move into the CMYK color space is due to the saturation values of the ink. A monitor can produce more saturation to a pixel, than a 4-color press can produce by mixing inks.

Use the Hue/Saturation 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.

Click the

Image menu, point to

Adjustments , and then click

Hue/Saturation .

Drag the

Saturation slider to the left until all the gamut masks disappear.

Record the Saturation Value used.

Click

Cancel .

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

Feather .

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 (Mac) to deselect the image areas.

The image is now ready for conversion to CMYK.

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