As a trainer, I hear from designers, photographers
and production staff who are regularly faced with
color-related frustrations. While no two creative
practices or workflows are alike, I’ve observed some
common threads of confusion, and I’m asked the
same questions repeatedly. To wrap up this latest
series on color management, I provide some
straightforward solutions and recommendations.
Q: I mainly work in print and convert my scans
and original artwork to the CMYK mode.
This is the first task I perform when I open RGB
images. I then proceed to crop and color correct
them. Why am I being asked to keep the images
RGB, only converting to CMYK at the very end? It
seems foolish to work in RGB when my final destination
is a press.
A: If you have an exclusive arrangement with a
print shop, then converting to the press colors
right away might be a reasonable option in some situations,
such as a compelling need to maintain a
simple workflow. In reality, flexibility is prized in
print projects where artwork ends up being printed
on multiple printers, presses and on different media,
including web publishing. CMYK colors, by their
very nature, are device-specific. In other words, the
CMYK color set belonging to one printer will be
significantly different from the CMYK colors produced
by another press or printer. At present, most
images start out as RGB images (scans, photos,
stock art, original illustrations, etc.). This is why
you’re advised to gather the images in a suitable
RGB working space to perform color corrections
and basic image editing. RGB working spaces such
ColorMatch RGB and Adobe RGB are uniquely
suited to host color correction for any final CMYK
output. This way you’re not committing to any one
set of CMYK colors too early in the game.
After corrections, save the master RGB files
as Photoshop (PSD) or TIFF files with the layers
intact. At output time, convert a duplicate to the
CMYK color space your printer recommends using
the Edit>Convert to Profile command. You’ll end
up with a CMYK image that is crafted to match the
final press, while your color-corrected RGB image
is safely archived until you need to perform another
color conversion for CMYK output.
Q: How can I verify if the lighting and viewing
conditions in my studio are suitable to view
images on screen, as well as for evaluating original
art and prints?
A: This is a common concern in many creative
studios that feature large windows, skylights
and specialized lighting. However, controlled lighting
calibrated to a “daylight” temperature of 5000
K is critical to the environment in which you view
and evaluate colors. Colors in the original or print
can look different under fluorescent, tungsten or
any other lighting source. Luckily, there are ways to
determine if your existing lighting is suitable to
properly evaluate your work.
One option is to purchase and use PIA/GATF
RHEM Light Indicator strips (figure 1). These are
special stickers backed with an impermanent adhesive
that can be attached to originals, proofs and prints.
These labels are used to validate the lighting conditions
used to view printed output. They are printed
in bands of two colors that appear as a single smooth
color when viewed under 5000 K lighting conditions
and appear banded when viewed under nonstandard
lighting. Each PIA/GATF RHEM Light Indicator
measures 2 x ¾ in. They’re available in booklets of 50
stickers. This makes for an inexpensive and portable
solution to determine the suitability of lighting at
your studio, print shop or the client’s office.
Another solution is to use a viewing booth
(shown in figure 2). These can be successfully used
under a wide scope of lighting conditions ranging
from darkened retouching rooms to brightly
lit reception areas and client offices. These viewing
booths use controlled lighting and have long been
used by print shops to show contract proofs and
press output. Now you can rely on portable and signifi
cantly cheaper desktop models that use the same
standardized lighting as their expensive counterparts
in pressrooms. Be sure to view, present and evaluate
your colors in the same viewing booth, ideally placed
at right angles to your monitor.
Q: I work in an ad agency, and I’ve been asked to
send a color-accurate PDF proof to my clients
to view and approve on their computer and office
printer. The final art will be printed on press. Is
there a way that I can ensure color accuracy for all
those viewing and printing my artwork after it
leaves my studio?
A: At present, a lot of printing done in North
America and Europe relies on PDF technology
as a vehicle to deliver print-ready files and for proofing.
To create final art that will preview and print
consistently at any location, I recommend using a
special flavor of PDF called the PDF/X standard.
When you save final art as a PDF/X standard, it
guarantees that colors and other variables in your
file are preapproved. In particular, color profiles in
these files are streamlined and validated, leaving
nothing to chance—such as careless or ignorant
production practices. Luckily, you can save these
files directly from Adobe CS2 Premium applications
such as Photoshop, Illustrator, InDesign and
Acrobat Distiller.
To create CMYK art for press output, first convert
all the images to a suitable CMYK color space,
using either a custom press profile or a standard reference
space such as US Web Coated (SWOP), US
Sheetfed Coated, etc. Then you should save a copy
as a PDF or export using the PDF/X-1a PDF Preset
from any of these applications.
For proofing and printing at the client’s site,
Lou Prestia, a color consultant specializing in PDF
workflows, suggests first asking your clients whether
they have calibrated monitors and proof printers
before agreeing to send a PDF file. If they have both,
ask how closely the printed proofs match their display.
If they report good matching of inkjet prints
to screen, and you supply a validated PDF file, then
your chances of success are greatly improved.
Prestia adds that for a PDF file to proof correctly
at the client’s site, the client will need a calibrated
display and standard viewing conditions (D50
lighting or a viewing booth) near the display. If your
clients plan to make a proof print, they will need a
high quality inkjet printer, utilize professional media
that can match and exceed the press colors and then
learn to convert the CMYK colors in the file to their
printer’s colors at print time. As most will agree, this
is a monumental task for most clients! A reasonable
alternative is to send along a low tech but reliable
hard copy as a proof.
Q: I’m looking for a studio printer that will give
me color-critical output of jobs that will eventually
print on press. Outputting photos is not my
primary concern; better PMS matching is what I’m
really after. I need the printer to be PostScript compatible,
as I use Photoshop, Illustrator and Quark
XPress in my work.
A: What you need is an inkjet printer driven by
RIP software. A RIP (Raster Image Processor)
runs on any desktop computer and is used to translate
the raster and vector files created by an application
into bitmapped or raster files for a specific
printer. Today, inkjet-plus-RIP combinations are a
common fixture in art departments, photography
studios, ad agencies and in-house prepress departments.
According to Jim Rich, consultant and
author of The RIP Report, inkjet printers with RIPs
are very easy to incorporate into any digital workfl
ow. They provide low cost, high quality printing
that features a wide color gamut to match most
commercial printing. They also offer enough resolution
to print halftone dots for proof simulation and
can be used with archival quality ink and paper.
RIPs are specialized to perform certain functions
such as page imposition, black and white photographic
output, better PMS matching and SWOPcertifi
ed color proofing. Rich adds that there are
over 70 inkjet RIP vendors with products that range
in functionality, price and ease of use.
Q: I have two digital cameras: one that captures
and saves images in sRGB and the other in
the Adobe RGB color space. The captured images
are viewed on screen, e-mailed, published to the
web and output to an RGB inkjet printer. Can you
recommend a streamlined workflow involving
working spaces and color conversions for all my
output methods?
A: Since your output is split between viewing
RGB art on screen and printing rich RGB
colors on your inkjet, I recommend that you standardize
on a larger, comprehensive color space. The
Adobe RGB working space fits this bill nicely. To
easily combine all your captures into this “container”
space, set up Color Settings as follows
(figure 3):
1. Choose Edit>Color Settings.
2. In the Settings menu, start by choosing the
North America Prepress 2 setting. This sets the
RGB working space to Adobe RGB.
Furthermore, you can automatically convert all
files in the sRGB color space to your chosen working
space by setting up the Color Management Policies
as follows: Set RGB to Convert to Working RGB
and uncheck the boxes for all the Profile Mismatch
and Missing Profile warnings shown. This will help
ensure a smooth workflow where all images saved
in the sRGB color space are automatically converted
to the larger Adobe RGB color space when opened
in Photoshop.
Recommended resources:
For information about
the PIA/GATF RHEM
Light Indicators, visit
www.gatf.org.
Viewing booth image courtesy of Just Normlicht, Inc.
Jim Rich, Rich & Associates
Lou Prestia, Prestia Color Consulting
