2013

Imagesetting 303
approximately what you see on screen (allowing for differences between screen and
printer colors).
If you convert the blend to editable shapes, the intermediate shapes lose all spot color
information. They separate only to CMYK. Only the final object prints as a spot color.
RGB and CMYK Blacks
Because shades of black and gray that are defined as RGB or HSV colors will separate
into a mix of all four CMYK process colors when printed, you can sometimes get less
than perfect gray shades. And any slight mis-registration of the CMYK color printing
process will sometimes be visible on the edges of black objects.
Although the theory is that an equal mix of CMY inks will give a perfect shade of gray,
it does not (and this is why the black "K" ink is added to the mix). So a gray that is
defined as an RGB or HSV gray will contain a mix of all four colors to improve the gray
color. But the best gray can be achieved by using only the K (black) ink plate. Thus if
you require perfect grays it’s better to use gray shades that are defined as a tint of a
CMYK "pure" black.
When creating documents based on the default templates designed to be printed,
such as US Letter or A4, then the shades of gray defined on the Color Line are defined
to be tints of pure "K" black. So if you use these gray colors from the Color Line, you
will get quality printed grays.
There is a corollary situation that a printed black that is based solely on the use of "K"
ink, is not that black. You can get far darker blacks by adding some of the other inks
printed on top of the black. So if you require really dark blacks for large objects or
areas, then you can define a CMYK color that has 100% K ink and a percentage of the
other colors (30% of each of the CMY colors is sometimes used).