Digital Prints

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Mastering Digital Printing
Kodak, on the other hand, has taken a slightly different marketing tack by claiming for
its Ultima Picture Paper that “other inkjet testing methods that only evaluate light fade,
for example, don’t present an accurate view of real-world picture display conditions.” Their
tests also include heat, high humidity, and air quality (ozone). Wilhelm is now doing some
of this too, but the manufacturers may or may not choose to report all the data.
Some vendors and distributors also do their own testing. InkjetART.com does both internal
and contract fade testing on some of the papers and inks that it sells, and Jon Cone’s
InkjetMall.com does 1,000-hour xenon-based fade tests with its in-house ink brand compared
to others. “Our testing is brutal when we look at how one ink/paper does against
another,” Cone says. Digital printing supplies distributor LexJet Direct contracts with
WIR to test its products.
The problem with vendor-sponsored tests and claims, besides an obvious bias, is that they
tend to generalize and simplify what is a very complex interaction of separate elements
that can contribute to significantly different results depending on the display or storage
conditions. There just is no standardized “miles-per-gallon” way to describe print permanence.
At least not yet.
Your Mileage May Vary
Permanence claims and estimates will vary depending on the specific display or storage conditions any
print experiences. Using WIR’s lightfastness tests as the model, it’s easy to see why this is. The point of
print failure (David Matz calls it “the death point”) is reached based on the total, cumulative light exposure.
The way that’s figured is by multiplying the lux level by the time of exposure, which yields the
total, cumulative amount of light in lux-hours.
Let’s say WIR has determined that the death point of a particular ink/paper combination is reached at
100 million lux-hours (that’s the equivalent of 30,000 lux over 3,333 hours or 139 24-hour days).
Extrapolating the results to WIR’s “standard” indoor conditions of 450 lux for 12-hour days, you would
end up with a usable print life of 50 years. But if the intended conditions are more like a museum where
100 lux might be used, then all of a sudden that same ink/paper combination now becomes a 228-year
rating. Or, if the print is going in your south-facing living room where 5,000 lux will hit it each day, the
print’s lifetime has just shrunk to 4.6 years. Big difference.
Kodak raised some eyebrows in early 2004 when they announced their Ultima Picture Paper that “delivers
inkjet prints that last more than 100 years.” Sounds good until you read the small print and discover
that Kodak’s reference display environment is 120 lux for 12-hour days, which they support with “typical
home” studies. Simply replacing 120 lux with WIR’s 450 lux would instantly drop that 100-year
longevity prediction to 26.7 years! This is why reading the fine print on these tests is so important.
Individual Artist Testing
There are many photographer-artists who, in an attempt to compare products and get
accurate information about their specific materials and methods, do their own permanence
tests. For example, working photographic artist Steven Livick (in collaboration with Bill
Waterson) combines lux-hour-measured, outdoor-sunlight testing with the use of inkjet
coatings to help him determine the longevity of his large-scale murals.