Print RGB/CMYK gray using black only

When the Print RGB gray using black only option is turned on, any RGB color that has equal R, G, and B values is printed as K-only black instead of CMYK black. Similarly, when Print CMYK gray using black only is turned on, any CMYK color, where C, M, and Y are 0 (zero), and K is any value, is printed as K-only black instead of CMYK black.

You can turn on Print RGB gray using black only or Print CMYK gray using black only for either Text/Graphics or Text/Graphics/Images. "Graphics" refers to vector graphics. "Images" refers to bitmap images.

Note: You can also turn on Print gray using black only for the Grayscale source profile, with the same options of Text/Graphics and Text/Graphics/Images.

The following limitations apply:

The Print RGB gray using black only and Print CMYK gray using black only options have no effect on a job that is sent as separations.
If CMYK rendering intent is set to Pure Primaries, Print CMYK gray using black only does not affect the output.
If Separate RGB/Lab to CMYK source is turned on, Print RGB gray using black only is turned off. Likewise, if Print RGB gray using black only is turned on, you cannot turn on Separate RGB/Lab to CMYK source.
If Black Text and Graphics is set to Pure Black On or Rich Black On, it takes precedence over Print RGB gray using black only and Print CMYK gray using black only for 100% black text and graphics.
If a gray is specified as a spot color, Print RGB gray using black only and Print CMYK gray using black only do not affect that gray.