Filter
Top Products
of our commitment to report image-stability data
a
ccurately and to maintain integrity and credibility
with our customers.
Kodak is very confident in the revolutionary image
s
tability of KODAK PROFESSIONAL ENDURA
Papers. To further demonstrate this confidence we
commissioned a major study with the Image
Permanence Institute at the Rochester Institute of
Technology. Through this study, we not only
achieved independent substantiation of Kodak’s own
internal testing, but learned that in fact our intrnal
claims were conservative.
Defining Print Life—
Degradation Mechanisms
Defining print life requires information on the
mechanisms that degrade prints and which
mechanism first becomes limiting. This often
requires knowledge of the environment in which the
image is stored or displayed, because different
degradation mechanisms may outweigh others in
different environments.
In silver halide-based color papers, four
mechanisms contribute to determining print life:
• degradation of the dyes caused by heat
• degradation of the dyes caused by light
• yellowing of the minimum densities (D-min) due
to light or heat
•
degr
adation of the resin base
F
or e
x
ample, a resin-based color paper may have
very high light stability but only mediocre resin
stabilit
y in the base. It will perf
orm very w
ell in
tests for light stability. However, if it is stored in an
environment where the base degrades faster than
the dy
es, ex
c
ellent light stabilit
y bec
omes
meaningless. In this example, degradation of the
resin base is the limiting mechanism.
These same four degradation mechanisms also
a
pply to inkjet materials. However, we must also
consider other mechanisms:
• ambient moisture (relative humidity)
• atmospheric pollutants
• direct water contact
• fingerprinting
A multitude of tests, reports, and conclusions from
many sources have described the significant
advancements made in inkjet light stability.
However, while the thermal stability of most inkjet
systems is quite good and very significant
improvements in colorant stability due to light
exposure have occurred, promotion of products
based on light-stability testing is extremely
misleading when it ignores the other important
degradation mechanisms. To describe print life
accurately requires taking all degradation
mechanisms int
o account. A material could have
excellent light- and thermal-fade performance but
poor print life if the colorant stability is poor when
exposed to moisture or atmospheric pollutants.
For a more detailed discussion of the degradation
mechanisms and image-stability performance of
Kodak inkjet materials, see the references
2,3
below
as well as the technical papers found at:
http://www.kodak.com/eknec/PageQuerier.jhtml?p
q-locale=en_US&pq-path=98#technical_papers
.
.
It is extr
emely important to recognize that
the life of the image may not necessarily be limited
by the stability of the image dyes. A manufacturer
who talks about “dye stability” or “light stability”
alone, or who uses only light-fade data to describe
the performance of a product, is very likely not
pr
esenting an accurate prediction of print life.
2
D.E. Bugner and C.E. Romano, “Printing Memories to Last a Lifetime:
Under
standing Imag
e Stabilit
y f
or Ink Jet P
rints,”
R
echar
ger Magazine, 13(1), 2001, pp. 134–140.
3
D.E. Bugner and P. Artz, “A Comparison of the Image Stability of Digital
Photographic Prints Produced by Various Desktop Output Technologies,”
Proceedings of the International Conference on Imaging Science 2002,
2002, pp. 308–310.
4