Published in New
How color management can
change the way you work
By Ron Ellis
Color management is now viable. Technological
improvements have come so far so fast, that color management is not only viable,
but it can change the way you work and help save you money.
The push to change
Printers
of all shapes and sizes are driving the need for improved color management
tools as the conversion in prepress continues toward computer-to-plate (CTP)
workflows.
First,
it became obvious to the early CTP adapters that color management was critical,
so printers began investing in color management systems (CMS) in their
Second,
inkjet proofers became faster and less expensive, suddenly
making color management more relevant – because even though these proofers are
dramatically less expensive than old proofing systems, they are useless without
color management.
Third,
the manufacturers of industry leading Raster Image Processor (RIP) equipment
that drive these proofers added color management capabilities to their software
so that the color management data can be easily used to control the proofs.
And
finally, manufacturers of other peripherals to support the industry such as
Apple for its hardware and software, Microsoft for its ubiquitous operating
systems, and Adobe for its Photoshop and other image manipulation software applications, understood the need for dependable color
management tools for the graphic arts industries. Thus, true useful color
management tools began to filter down to all levels of users.
What are the
benefits of color management?
Two
of the greatest benefits of appropriate use of color management are that proofs
are accurate — including some ability to soft-proof a job on a computer
monitor, and the significant cost savings involved.
As
long as color profiles are accurate (more on this topic later) and depending on
the type of job to be printed, some proofing can be done looking at the proof
on a computer monitor, saving time and money.
Additionally,
the costs of hard proofs can be reduced dramatically. A Matchprint
can cost as much as $70 when labor and materials are factored. A proof from an
inkjet printer can cost as little as $1.50.
By
using an inkjet device that has a large color gamut and color management, spot
colors can be produced more accurately than with traditional analog proofing
systems and as well as most high-end digital proofing systems. Instead of using
a generic standard such as Matchprint, the proofing
simulation can be customized to represent the exact press or process used in
your
One
negative aspect of color management is that it can be confusing and difficult
in the beginning. Having experienced help can get you there faster with less
pain.
Nearly all color management systems are based on the
use of color profiles. The standards for these profiles were developed by the
International Color Consortium (ICC). In the past, most color management
systems used proprietary methods of describing and correcting color. If you
were not an experienced scanner operator, you probably found it difficult to
describe and correct color for your clients. ICC profiles take much of the
guesswork out of managing color.
ICC
profiles use the LAB color space (a device independent color space) that
contains a wide gamut for mapping colors outside of the normal RGB and CMYK
color models. By attaching an ICC profile to a document, an application can
change how those colors are displayed or printed.
“In
an ICC workflow, profiles can be used in two ways,” said
“Secondly,
profiles can be used to simulate the look of one device on another (typically
called “proofing a device”). In the second case, the proofing device
should replicate the limitations of the device being proofed, even though it
may be capable of printing a wider range of colors,” Levine said. “For example,
a dye-based inkjet proofer can be used to simulate the
look of a standard web offset press (SWOP).”
The
profile itself is only part of a CMS workflow. The RIP software being used must
support ICC profiles. Not all software supports ICC profiles in the same
manner. For example, the RIP driving a proofer or platesetter must
support ICC profiles in order to make use of these profiles. Different RIPs use different CMS engines to interpret the ICC
profiles and apply needed transformations. So even though an ICC profile
describes a device, different RIPs software will use
that profile differently and with differing results.
The
big idea is that not only do you need an ICC profile, but a RIP or software
that implements the CMS transformations correctly. A good example is Adobe
Photoshop. Photoshop not only uses ICC profiles and has a built-in CMS engine,
but the results are spectacular and many users report good results using color
management and Photoshop.
In
contrast, Adobe PageMaker also can use ICC profiles and has integrated a CMS
engine, but PageMaker has trouble showing images on screen and is not
recommended for using ICC profiles to soft-proof results prior to printing.
To
summarize, color management requires not only ICC profiles, but software or a
RIP that takes advantage of these profiles. When working properly, you insert
the profiles in your RIP software, and when you print, the RIP will use these
profiles to give you the simulation you desire. To do this, two different
profiles must be created.
The
first profile is typically called a destination profile and is used to make the
output device print as accurately as possible. The second is called a source profile and
is used to simulate or show the limitations of the device being emulated.
ICC
profiles can be created for a display monitor, for a scanner, and for output
devices. In addition the output device may use another device’s profile in
order to simulate that device itself. (For example a monitor or an Epson proofer can both use a Matchprint
profile to simulate how the Matchprint will appear.)
These
profiles can be used in many ways to help smooth production. The most common
ways these profiles are used is to create simulation proofs, improve quality, softproofing, and to cut costs. For example, several
profiles are used to create a simulation proof of a Matchprint
on an Epson 10000 inkjet printer. The destination profile is of the Epson 10000 and
is used to help the Epson itself produce color as accurately as possible and to
get the widest possible color gamut out of that printer.
The
second profile is the source
profile and will represent the Matchprint proofing
system that is being emulated. Both profiles will be applied in the RIP. For
example, the destination
profile is used to make the Epson print as accurately as possible, and the source or Matchprint profile is used to limit the colors down to the
characteristics of the Matchprint.
It
is important in this example that the Epson have a larger color gamut available
to it than the color gamut of source profile, otherwise the Epson will
not be able to accurately represent all of the colors to be translated from the
reference (Matchprint) profile. In addition, in some RIPs, spot colors outside the color space used by the source
profile can be mapped to the space used by the Epson allowing you to accurately
represent hard-to-show spot colors.
In
addition, if the RIP allows mapping of spot colors, and the color gamut of the
printer is larger than that of the destination profile, you may be able to get
really good results proofing spot colors. For this to be the case, you must
have a proofing device with a large color gamut, as well as an RIP that allows
you to map the non-CMYK colors in LAB rather than the already limited
CMYK. (A good example of this is the Best ColorProof
RIP and the Epson 10000, which together have a good reputation for being able
to reproduce spot colors). Being able to accurately reproduce spots colors is
not a given however.
“An ICC profile does not expand the gamut of a
printer, it quantifies it,” said Levine of Monaco Systems. “Using a quality
profile for an output device can maximize your ability to reproduce color
within a device’s gamut, which in the case of printers, is primarily determined
by the ink and media combination used by the output device.
“A
common misconception is that the addition of light printing ink substantially
increases the gamut of a device,” Levine said. “In reality, light inks provide
little or no increase to gamut size as they are only “watered down” versions of
their darker counterparts. Light inks are used specifically to increase image
smoothness and not to expand the device gamut.”
The same source profile being used to make the Epson
simulate the proof can also be used to make a monitor and copy of Photoshop 6 simulate
the proof. Once the monitor is calibrated, the proof profile is picked in
Photoshop and can show characteristics of the source profile.
What is a
good candidate for profiling?
In
many shops an analog proof such as a Matchprint or
Waterproof is a good candidate for color profiling. That is because these
proofs represent the only known and stable point in the printing process. These
proofs are based on one stock, with fixed exposures and quality control, and if
these analog proofs can be matched on press then they are a good starting
point.
If
the proof cannot be matched on press and is not accurate, or if the site is
using a CTP workflow where there is no proof at all, then the press can be
profiled.
In
order for this to be successful, the pressroom needs to understand densitometry and
should be able to run the numbers. In this case, the targets are printed on
press on the common coated and uncoated stocks, and profiles are made. If there
is good process control in place then these profiles will be accurate, and will
show an even better representation of what you will see on press than profiling
the analog proof.
“Color
management has grown out of process control,” Levine said. “Process control
keeps your devices stable. Color management communicates color between them. If
you start with good process control, you will be successful. If not, you may
find yourself wasting time and effort.”
The
profiles are created by using color management software and a
spectrophotometer. Typically creating a profile involves printing out a series
of color patches and reading them back into the CMS. Patch sets can contain
from 300 to 1,900 patches with about 1,000 patches being the most common. The
more patches you read, the more accurate the results will be. The patches are
read back into the software using a spectrophotometer.
The
software then compares what the patches should be and the measured result can
then be used to create a profile that accurately represents how the device
being profiled represents color. The most popular color profiling software is
made by
In
general however, ICC profiles can be used interchangeably with systems from
different manufacturers. (RIPs however use these ICC
profiles in many different ways with different levels of success). The most
popular graphic arts and prepress products are Monaco Proof and Profiler and GretagMacbeth’s Profile Maker.
All
of these products allow you to interface with the most popular
spectrophotometers and allow you to print patches, capture data, and create
profiles using a number of settings regarding rendering intents, total ink
coverage, black generation, and other settings that affect how the profile
functions.
All
of these products allow you to edit the profile as well. These products range
in price from $1,500 (Monaco Proof) to $4,500 (Monaco Profiler and GretagMacbeth Profile Maker). Generally, the more you pay,
the more control you have over the profile creation product. There are also
some entry-level products such as Monaco EZColor for
$300 that uses a scanner instead of a spectrophotometer to read patches. This
product can give surprisingly good results, but does not offer the same level
of professional control as the high end products.
The
most common spectrophotometers are GretagMacbeth’s Spectroscan and the X-Rite DTP41. The Spectroscan
is completely automated and costs approximately $5,900. The DTP-41 is a strip
reader and requires you to hand feed strips and cost approximately $3,200.
There are also several hand-held spectrophotometers such as GretagMacbeth’s
Eye One and Avantes’ Spectrocam
which cost approximately $1,500. For profiling inkjets, a UV filter is
recommended for all of the above in order to compensate for brighteners
commonly found in inkjet papers. For profiling monitors, all of the above
except the DTP41 can be used, although there are a variety of inexpensive
instruments such as the Spyder or the Monaco Sensor
which are only recommended for monitors and sell in the range of $300. (
The
most difficult part of color management is implementing the profiles properly
into your workflow. The process can be confusing at first. It can help to have
a consultant or trainer used to the process. The trick is to discover where in
the workflow to apply the profiles to get the best results. It can be
challenging because every RIP handles color management differently and some
give you more control than others.
Even
though there are many RIPs that can drive proofers,
sometimes the aftermarket RIPs give you more control
over color transformations than using the actual RIP that will be making the
plates. For example, many traditional RIPs convert
the data into CMYK and eliminate the ability of the profile to translate the
spot colors in the wider colorspace of an inkjet proofer. In this instance, the colors are forced to CMYK
and it is doubtful that hard-to-match spot colors will have any hope of being
accurate. The trick is to figure out which combination of tools such as RIPs, color management software, instruments, techniques
and workflows will give you the results you need. A couple days of a good color
management consultant who has experience with many workflows and printing
processes can save days of wasted time and take thousands of dollars off the
learning curve.
Color
management offers many potential benefits. Although there is a lot to think
about, the tools have matured and exist to take advantage of all that color
management has to offer. The time is right now for color management. The
technology works and the return on investment can save a significant amount of
money in proofing and quality control.
Ron Ellis is a prepress consultant specializing in workflow training and
integration. He worked in the commercial printing industry for 18 years and
brings a strong background to all aspects of prepress. He has consulted on
numerous CTP installations and he provides color management, integration,
training, workflow
development, and troubleshooting solutions to the graphic arts community. He
can be contacted at 603-498-4553 or through his web site at www.ronellisconsulting.com.