Graphics Programs Reference
In-Depth Information
You have robust soft proofing tools and if conducting color conversions,
ACE CMM, Black Point Compensation, and dither are available. The
images will have embedded profiles and once all this work is complete,
the files are correct for output and only need to be linked (or optionally
embedded) in the pages. The trick becomes figuring out how to turn off
color management in these page layout applications so no further
conversions take place by accident. In Quark, that's as simple as unclick-
ing the
Color Management Active
check box in the color management pref-
erences. InDesign works like Photoshop so the documents with
embedded profiles in print/output spaces should be treated correctly. Of
course, how the document is printed (print driver or RIP settings) will
still be a factor.
If you are providing documents to clients for insertion into a page
layout application, providing them with color-managed documents with
clear instructions will work as long as you know what print/output space
they intend to use. This is where having an RGB pipeline can be benefi-
cial yet potentiality dangerous. Suppose you supply all your tagged
images in Adobe RGB (1998). The upside is that once the page is created,
the end user can apply an output profile in the print chain so they can
proof the pages on their desktop printer. Then they can send the same
page to the final output device using the profile for that print process.
They don't need multiple pages in multiple print/output color spaces.
This is sometimes known as
Late Binding
or
In RIP separation
, the latter
name due to the RIP handling the output color space conversion when
printing. The main advantages of this approach is flexibility. No one wants
to swap out hundreds of images and other page elements each time they
need to print a job. Keeping all this data in a tagged RGB color space
means that the page can be output to any output device as long as an
output profile exists. The downside is this is a far more complicated
process and until ink hits the paper, we really have no idea if the color
is what we want. Fortunately, for most photographers, these issues don't
come into play. For the designer and certainly, for those in prepress, the
decisions to embrace early or late binding is a critical factor in the
pipeline.
Sidebar
Device Link Profiles and CMYK-to-CMYK Conversions:
Sometimes, the ability to convert
from an original file from RGB to CMYK isn't possible. If an existing CMYK document exists but
it needs to be reseparated into a new flavor of CMYK, there are a several issues to consider.
One potential problem with CMYK-to-CMYK conversions is that the black generation can
change since the conversion is from CMYK to PCS (CIELAB) then back to CMYK. This will affect
solid black items like text or drop shadows that were intended to print with only black ink. A
new mix of CMY and K inks will be used instead of just black ink.
One method that is a solution to this problem is to use a type of ICC profile called a
device
link
. A device link is like two profiles hardwired into one. There is no Source and Destination
