With more than 41 years of experience in photography, design, prepress, printing, and color science, Don Hutcheson has pioneered many techniques we now take for granted, like RGB workflows, soft proofing, extended-gamut printing, and digital proofing.
In 1995 he started the world’s first color management consultancy, HutchColor, LLC, to bring the concept of ICC color management to professional graphic users. Today he continues to train the world’s top printers, publishers, agencies, photographers, and designers through private consulting and public conferences.
In 2006 as chair of the IDEAlliance GRACoL Committee, Hutcheson used his own proof-to-press calibration method (now known as “G7®”) to produce the current GRACoL and SWOP data sets. Since then G7 has made standardized printing and proofing easier and more accessible to thousands of printers and print buyers world-wide.
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CR: Let’s start
with a bit of history. How did you first come to be interested in digital
color, and what kind of training prepared you for the career you now have?
DH: Digital
color is the child of desktop publishing, which evolved from electronic color
scanning, which in turn evolved from graphic arts photography or “color
separation” – one of the key enabling technologies in the development of color
printing. Like all printing, digital color is therefore simply a form of
photography, which has been my passion since I was 13, so its natural that I
should be interested in it.
From 18 thru 22, I served a
five-year apprenticeship as a graphic arts camera operator at a company called
Photo Engravers, Ltd. In Auckland, New Zealand. When they bought one of NZ’s
first electronic drum scanners – a Hell C-296, the union wanted it to fail and put
me on it with nothing but a badly-translated German manual.
I twiddled every knob and made
every mistake you can imagine, including one day removing all the unwanted inks
and replacing them with black. When that job hit our 1-color proofing press a
few days later, it was like nothing anyone had ever seen before and I was
nearly skinned alive, until they added the black plate, when suddenly
everything looked wonderful. Today we call that GCR.
Though designed for CMYK work, I
saw the scanner’s photographic potential and found I could make just three RGB
negatives and print them onto photo paper through RGB filters. With a little
experimentation I was able to make prints that matched not only the color of an
original transparency, but also the subtle highlight and shadow details with a
level of perfection hitherto unobtainable by analog means.
Although the C-296 was not a
digital scanner, it was my first experience of what we now call digital imaging
and I’ve been hooked ever since.
CR: Your career has
spanned several decades – what are some of the technologies that have come and
gone during that time?
DH: Continuous-tone
camera separations, direct-screening camera separations, tray development,
nitrogen burst development, glass screens, contact screens, silver masking,
tri-pack masking, double-overlay masking, wet etching (with potassium cyanide!),
dry etching, film stripping, ruby masking, analog proofing (AgfaProof, DuPont
Cromalin, DuPont WaterProof, 3M Color Key, Transfer Key, and MatchPrint, Remak,
etc.), drum scanning – you name it.
CR: Is there any
technology or ideology that has faded from use that you might hope we
re-discover? Or what might be the next bleeding edge tech in the world of color
management?
DH: I’ve
always loved the early continuous-tone printing methods like Collotype, partly
because there are no dots to interfere with fine image detail, but also for
their purity of color. Halftone printing imposes some color space limitations
that don’t exist in true continuous-tone printing, where ink film thickness is
varied rather than dot size. If someone invents a practical way to print truly continuous-tone
CMYK with offset or digital efficiency, it will have a dramatic impact on
fine-art reproductions and expanded-gamut applications.
As for the bleeding edge of color
management, today’s biggest challenge is the huge difference between the official
D-50 illumination standard and the actual light sources in viewing and
measuring equipment. Color management is based on the assumption that we can
measure color as it is seen by the human eye, but we are far from achieving
that to a high level of accuracy.
The problem lies in the D-50
standard itself, which defines the quality of “standard white light” as a graph
of emitted energy vs. spectral wavelength. Unfortunately, the D-50 spectrum is
based on hypothetical “daylight”, rather than any commercially-available light
source, so D-50 can only be crudely approximated by today’s viewing and
measuring equipment. This means certain inks, dyes, papers, etc. can measure quite
differently than they appear in a so-called D-50 viewing booth, and often an
excellent “measured match” (with effectively zero delta E) can look
unacceptable visually, and vice-versa. This disconnect between the D-50
standard and real-world light sources becomes even more of a problem as the
demand grows for ever-higher standards of measurable color accuracy.
The obvious solution is to replace
the D-50 standard with the spectral curves of a commercially-available light
source, such as the fluorescent tubes used in today’s viewing booths, or some
new LED equivalent, but agreeing on a new light source is fraught with political,
economic and patent issues. Meanwhile, there are work-arounds that can reduce
or eliminate the problem, but because they deviate from the D-50 standard, they
are difficult to implement en masse. The new M1 measuring standard solves part
of the problem but is far from a complete solution, and has in many cases
exacerbated, rather than reduced, the related problem of OBA-enhanced papers,
which fluoresce under UV light.
CR: Let us now
discuss the G7 protocols and their evolution – can you walk us through some of
the early days of G7?
DH: Around
1980 I developed a simple way to calibrate a color scanner to match the
tonality of one printing or proofing system on another. At the time, “Dot Gain”
(now called “TVI”) was the accepted basis for press calibration, but I found
that consistent dot gain failed to give consistent visual appearance with
different press conditions or technologies, like offset and pre-press proofing.
To solve the problem, I developed a
simple neutral density-based technique that achieved a perfect visual match on
neutral grays, regardless of inks or technology. But if the dynamic ranges of
two devices didn’t match, I had to tweak the graphs to meet at the shadow point,
while keeping highlight regions identical. That “shadow compression-expansion”
principle remains one of the key features of G7, and the technique I used back
in 1980 is still alive today in the free G7 Graph Paper Method.
Fast-forward to the 1990s when CtP
removed film from the plate making process and the question became “what do we
calibrate?” Previously we linearized the scanner or film setter, but now you
couldn’t do that. So I put my 1980’s method into an Excel spreadsheet that allowed
any press to match the tonality and gray balance of any printing or proofing
system, and called the process “P2P” for proof-to-press or press-to-proof.
In 2004 the GRACoL committee used
the P2P process to help develop the new GRACoL 2006 color space. We followed
all the ISO 12647-2 rules except the obsolete TVI curves, which we replaced
with NPDC (Neutral Print Density Curves) averaged from a number of ISO-standard
press runs made with un-calibrated plates. The same shadow-weighted algorithm from
1980 was used to adjust the NPDC curves in shadow areas to fit any printer’s
dynamic range, while preserving crucial highlight tonality.
To standardize gray balance, we followed
the logic of the ICC’s relative colorimetric rendering intent, defining CMY
gray balance as a function of paper color, reduced in proportion to dot
percentage. This also mimics the human visual system’s “chromatic adaptation”
phenomenon, and a camera’s auto white balance function.
GRACoL2006 and its sister SWOP2006
color spaces were wildly successful but to our surprise, many people were more
interested in the P2P calibration method, so I donated it to Idealliance who
re-named it “G7”, and the rest is history.
CR: You encountered
a lot of resistance initially. Can you give us some insight as to what that was
like?
DH: A
fundamental rule of science is that any new discovery should be challenged
rigorously. And a fundamental law of human nature is to resist change for
change’s sake. So it’s not surprising that some industry experts and
associations with a vested interest in the old TVI calibration method did their
best to kill G7.
The main opponents to G7 were
FOGRA, ECI and BVDM – three German associations roughly equivalent to
Idealliance, that do great work in promoting standardized printing in Europe.
In 2005 I offered the P2P system
freely to FOGRA and ECI, and suggested they partner with Idealliance in its
development. But the request went unanswered until January 2006, when they
announced their PSO certification system, which had been developed in secret
while G7 was an open, public project.
PSO is based rigidly on the ISO
12647-2 standard, with emphasis on TVI curves, while G7 exposes the weaknesses
of TVI and provides a more effective alternative. G7 was obviously seen as a
threat to the revenue potential of PSO, but the PSO program could easily have replaced
TVI with G7, or offered the option of TVI or G7. Instead those organizations refused
to acknowledge G7’s many benefits, and took instead an aggressive public stance
against G7, Idealliance and myself personally.
The good news is that ten years
later, G7 has been far more successful than PSO, largely because it works more
effectively, is far less expensive and can be used on any printing system, not
just offset. There are now hundreds of G7 Master sites and thousands more
unregistered users world-wide. In fact many German and European printers and
print buyers have secretly adopted G7 – they just don’t advertise it.
CR: When did you
know that G7 was going to become the de facto standard?
DH: As
soon as we released GRACoL2006, it became obvious that much of its appeal was
in the G7 calibration process. In 2006, Idealliance provided the G7 How-To and
GRACoL and SWOP profiles freely, with thousands of downloads in the first few weeks.
Printers all over the world began praising G7 as the first really useful
calibration system they’d ever tried, even if they weren’t printing to GRACoL. Other
processes like Flexo, screen, xerography, gravure, etc. also adopted G7 because
it made life easier – especially when they had to come as close as possible to
a GRACoL proof without the benefit of ICC color management.
CR: What are some
misconceptions some folks might have about adjusting color through grays?
DH: The
most common misunderstanding about G7 is that it’s a replacement for ICC color
management, which is not true. G7 uses just four one-dimensional curves to
achieve good gray balance and tonality, much as a photograph’s exposure and
color balance problems can be “corrected” in Photoshop with RGB curves alone. When
grays are corrected, colors are moved in the right direction, but may fall
short of complete accuracy depending on additional factors that cannot be
corrected with simple 1-D curves, like ink hue, trapping and opacity.
By contrast, ICC color management
uses more complex n-dimensional Look-Up Tables (LUTs) to apply hue, saturation
and lightness changes discretely to different colors. G7 generally does a
better job on neutral grays, however, and provides several additional benefits,
so the best of both worlds is to use a combination of G7 plus ICC.
CR: Is there any
color device that cannot be brought to G7 standard?
DH: No,
but systems that don’t have user-programmable 1-D LUTs may not be compatible
with the G7 calibration method. In those cases, ICC profiles can simulate a
G7-based color space like GRACoL, with the same visual effect, but without the special
benefits of separate G7 calibration.
CR: Are there any
particular books, white papers, YouTube channels or other reference sources you
might recommend to color management beginners?
CR: What are you
working on now? How’s it going?
DH: As
a photographer, one of my life-long passions has been “expanded gamut”
printing, i.e. getting more color out of conventional printing to make it look
more like photography. My most recent efforts in that regard contributed to the
new Idealliance XCMYK color space and methodology, which is based on maximizing
the color gamut of four-color offset and can be simulated on any digital color
system with sufficient gamut. In 2017 Idealliance will extend that work to consolidate
and standardize both 4-color and 7-color expanded gamut strategies, ink sets
and workflows.
CR: I know you are
a great lover of IPA’s. Got a favorite, and why?
DH: America
is blessed with the greatest selection of micro-breweries in the world. The
beer I drink most often is Dale’s Pale Ale, whose red, white and blue can prevents
oxidation by light. Dale’s has an excellent balance of hops without the excessive
alcohol levels that spoil so many IPAs. Other good brews include Sierra Nevada,
Anchor Steam, Lagunitas, Stone, and many others.
Many, many thanks to Don for taking time out of his busy schedule to speak with us.
To see and hear Don speak about the G7 protocols, as they apply to wide format printing, click
HERE.
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Do you have a color management question, horror story or event to share?
Email me at reilley4color@gmail.com
After some testing - OK, it was four and half hours of testing - we determined that it was the GCR causing the issue.
