Digital BW, The Print

In a post by "yohnnyboy"  chhopk@... the writer brings up an issue that demands 
consideration.  He asserts that the Wilhelm data is misleading.  His point seems well taken:  
since Wilhelm's tests are based on fluorescent lighting, they in no way reflect accurately 
what we can expect for print life for our prints which are exposed to daylight which is 
much stronger lighting.  The old apples and oranges analogy.  He refers readers to http://
www.livick.com/welcome.htm to Stephen Livick's rather detailed and extensive testing of 
print longevity.  I've read much on the Wilhelm site and much on Livrick's site and the 
latter seems to me to make much more sense and is a much more scientific approach than 
Wilhelm's.  I don't question the accuracy of Wilhelm's testing using fluorescent lighting.  
At this point I am convinced that Livrick's testing procedures are eminantly more 
trustworthy than Wilhelm's since they deal with criteria more consistent with the realities 
of fine art exhibiting.  On his site, Livick states:  "…if the fundamental underlying premise 
of your fade testing regime is fatally flawed, that of using impotent fluorescent lighting to 
perform your testing, then it's simply nothing more than phony grossly inflated ratings 
that are being produced and then being hyped by the ink jet manufacturers."  He also 
states, when comparing the true fading factors of Ultrachrome ink, that:  "…a more true 
rating would be just 1/3 of what ever is being stated for Ultrachrome ink on various 
papers when they were tested under fluorescent conditions."  He warns that we are being 
conned and manipulated by commercial interests if we believe them.  Consider, if we cut 
our expectations to 1/3 of what the manufactures states in longevity we fall to a print life 
expectancy of only, in the case of some Epson papers like Premier Lustre to only about 
25-30 years which is roughly about the same as a well-done drug store print life.  This is 
not what a fine art photographer wants to hear.  Have we been conned?  Those on our 
forum might want to express their views on this issue.  I for one feel now somewhat in a 
quandary.  I can't tell someone that a print will last a century when I might outlive the 
print and I'm no young fellow.  So, you folks out there with the knowledge of these 
matters, please share your thoughts.  This is a matter that affects us all.
Joe Davajon

Joe Davajon wrote:


> since Wilhelm's tests are based on fluorescent lighting, they in no
> way reflect accurately what we can expect for print life for our
> prints which are exposed to daylight which is much stronger lighting.


I'm not familiar with Wilhelm's methods, nor terribly familiar with 
Livick's. But I am familiar with fluorescent lighting. What I know is 
that you can easily get a fluorescent tube that emits totally within the 
  UV; you can get one that is strongly blue; you can get one that does 
near-IR; in fact, if you want to specify a bandpass, you can get a 
fluorescent light to fill it. "Fluorescent light" does not necessarily 
refer to workshop tubes you pick up at Home Depot. And you can certainly 
generate some flux - I worked with a UV fluorescent once that was bright 
enough to give you a sunburn in about 15 minutes if you were working ten 
feet away. Lots of safety requirements had to be met before you could 
work in that lab.

So to me, saying "Wilhelm uses fluorescent lighting, which is lame" 
sounds like it *might* be axe grinding. There isn't enough information 
in the statement to draw any conclusions, but it is obviously intended 
to disparage methodology. The questions you really have to answer is 
*what kind* of fluorescents does he use, what is the aggregate spectral 
curve of the lighting, and what is the incident flux on the fade test media?

I'm unimpressed with discussion of prints which are "exposed to 
daylight," as this is completely meaningless. A print exposed to a 
year's worth of daylight in a sunny room where I currently live (north 
latitude 61.5, in a cloudy climate) is going to last quite a while; a 
print exposed to daylight where I used to live (north latitude 31.5 in a 
clear desert, sun-beating-down-all-the-time kind of place) is going to 
be lucky to look unfaded after a month. Daylight is no standard. If you 
can tie your tests to flux and time, you can at least extrapolate a 
likely lifetime for the print in a given display condition. If you base 
your discussion on "daylight" without specifying the same things I 
indicated in the paragraph above, it means you don't really *know* anything.

--
Jeff Medkeff
Eagle River, Alaska

> In a post by "yohnnyboy" chhopk@... the writer ...
> asserts that the Wilhelm data is misleading. ...
> since Wilhelm's tests are based on fluorescent lighting, 
>they in no way reflect accurately what we can expect for print 
> life for our prints which are exposed to daylight ...

Sunlight contains a lot of energetic, short-wavelength UV that is filtered
out by standard window glass.  So, for outside display UV coatings are much
more important, and prints can be expected to last much less time. 

I think Wilhelm is fairly clear that he tests for indoor display.  For that
I think his work is fine, although any "years of display" estimate must be
taken as a very rough estimate that is subject to lots errors due to
differing display conditions.

Livick prefers sunlight, but that is only better if you'll be displaying
your prints in sunlight.  Aside from the UV content of direct sun, it is
probably the amount of light -- the intensity -- that is most relevant.  So,
the relative results of testing with either should be close.

How one defines the "normal" display lighting conditions is an issue Wilhelm
has pointed to in his criticism of what Kodak is doing.  Kodak seems to
assume very dim normal display lighting.  I'm not sure what the "correct"
amount of light is, but when it comes to stating results in terms of "years
of display" the assumption about display light intensity obviously has a
direct bearing.  

Other factors like humidity may also be important.  The brighter and hotter
the light, the more the print will be artificially dried and the results
exaggerated.  On the other hand, excess heat might be more like accelerated
aging than fade testing.  Many companies use the Xenon faders, which are
very fast and hot.  I think MIS used one of these for its UT testing.  With
the commercial Xenon light faders there are usually filters that one inserts
to change from outdoor to indoor lighting conditions.  Sometimes what filter
was used is not clear when the results are displayed.  However, this might
make a difference.

I don't think any procedure is perfect, so I look at all the results and try
to learn what I can from them.

For my own uses, I find fluorescent light easier to control in terms of
consistency and repeatability.  It's cool and efficient, but it also takes a
long time.  

I just do comparisons of test strips that are in the fader at the same time,
and I only look at the relative results.  Assigning a "years of display"
seems like a stretch.  So, I'll leave that to others (and let them defend
the results).

Paul
www.PaulRoark.com

I have never read the Wilhelm years as human-years but rather as print-years
(sort of like dog-years). It seems to me that these results are most useful
as relative results, 200 print-years is twice as long as 100 print-years but
neither are meant to be calendar years.

I think that everyone agrees that the conditions for display (note that even
Wilhelm's results vary widely based on glass, no glass or uv glass) effect
longevity and therefore - mileage may vary. Of course all works on paper
should be displayed in relatively low levels of illumination, with constant
humidity, and protected by glass. These are basic rules of conservation and
if they are ignored most artworks, regardless of the medium, will have a
shorter lifespan. We all know that sunlight fades everything except skin,
where too much causes cancer. Too much sun is bad.

Wendel

> In a post by "yohnnyboy"  chhopk@... the writer brings up an issue that
> demands consideration.  He asserts that the Wilhelm data is misleading.  His
> point seems well taken:  since Wilhelm's tests are based on fluorescent
> lighting, they in no way reflect accurately what we can expect for print life
> for our prints which are exposed to daylight which is much stronger lighting.
> The old apples and oranges analogy.  He refers readers to http://
> www.livick.com/welcome.htm to Stephen Livick's rather detailed and extensive
> testing of print longevity.  I've read much on the Wilhelm site and much on
> Livrick's site and the latter seems to me to make much more sense and is a
> much more scientific approach than Wilhelm's.  I don't question the accuracy
> of Wilhelm's testing using fluorescent lighting.  At this point I am convinced
> that Livrick's testing procedures are eminantly more trustworthy than
> Wilhelm's since they deal with criteria more consistent with the realities of
> fine art exhibiting.  On his site, Livick states:  "Šif the fundamental
> underlying premise of your fade testing regime is fatally flawed, that of
> using impotent fluorescent lighting to perform your testing, then it's simply
> nothing more than phony grossly inflated ratings that are being produced and
> then being hyped by the ink jet manufacturers."  He also states, when
> comparing the true fading factors of Ultrachrome ink, that:  "Ša more true
> rating would be just 1/3 of what ever is being stated for Ultrachrome ink on
> various papers when they were tested under fluorescent conditions."  He warns
> that we are being conned and manipulated by commercial interests if we believe
> them.  Consider, if we cut our expectations to 1/3 of what the manufactures
> states in longevity we fall to a print life expectancy of only, in the case of
> some Epson papers like Premier Lustre to only about 25-30 years which is
> roughly about the same as a well-done drug store print life.  This is not what
> a fine art photographer wants to hear.  Have we been conned?  Those on our
> forum might want to express their views on this issue.  I for one feel now
> somewhat in a quandary.  I can't tell someone that a print will last a century
> when I might outlive the print and I'm no young fellow.  So, you folks out
> there with the knowledge of these matters, please share your thoughts.  This
> is a matter that affects us all. Joe Davajon

I suspect the only truth one can say is if you conduct a test of different
ink/paper alongside each other for the same time then under those
conditions, and those conditions only, one or the other will last longer.
So all you can really do is pit them against each other and choose the best
available rather than predicting their life expectancy.

> From: Paul Roark <paul.roark@...>
> Reply-To: <DigitalBlackandWhiteThePrint@yahoogroups.com>
> Date: Fri, 17 Jun 2005 23:00:46 -0700
> To: <DigitalBlackandWhiteThePrint@yahoogroups.com>
> Subject: RE: [Digital BW] Wilhelm vs. Livick?
> 
>> In a post by "yohnnyboy" chhopk@... the writer ...
>> asserts that the Wilhelm data is misleading. ...
>> since Wilhelm's tests are based on fluorescent lighting,
>> they in no way reflect accurately what we can expect for print
>> life for our prints which are exposed to daylight ...
> 
> Sunlight contains a lot of energetic, short-wavelength UV that is filtered
> out by standard window glass.  So, for outside display UV coatings are much
> more important, and prints can be expected to last much less time.
> 
> I think Wilhelm is fairly clear that he tests for indoor display.  For that
> I think his work is fine, although any "years of display" estimate must be
> taken as a very rough estimate that is subject to lots errors due to
> differing display conditions.
> 
> Livick prefers sunlight, but that is only better if you'll be displaying
> your prints in sunlight.  Aside from the UV content of direct sun, it is
> probably the amount of light -- the intensity -- that is most relevant.  So,
> the relative results of testing with either should be close.
> 
> How one defines the "normal" display lighting conditions is an issue Wilhelm
> has pointed to in his criticism of what Kodak is doing.  Kodak seems to
> assume very dim normal display lighting.  I'm not sure what the "correct"
> amount of light is, but when it comes to stating results in terms of "years
> of display" the assumption about display light intensity obviously has a
> direct bearing.  
> 
> Other factors like humidity may also be important.  The brighter and hotter
> the light, the more the print will be artificially dried and the results
> exaggerated.  On the other hand, excess heat might be more like accelerated
> aging than fade testing.  Many companies use the Xenon faders, which are
> very fast and hot.  I think MIS used one of these for its UT testing.  With
> the commercial Xenon light faders there are usually filters that one inserts
> to change from outdoor to indoor lighting conditions.  Sometimes what filter
> was used is not clear when the results are displayed.  However, this might
> make a difference.
> 
> I don't think any procedure is perfect, so I look at all the results and try
> to learn what I can from them.
> 
> For my own uses, I find fluorescent light easier to control in terms of
> consistency and repeatability.  It's cool and efficient, but it also takes a
> long time.  
> 
> I just do comparisons of test strips that are in the fader at the same time,
> and I only look at the relative results.  Assigning a "years of display"
> seems like a stretch.  So, I'll leave that to others (and let them defend
> the results).
> 
> Paul
> www.PaulRoark.com

--- In DigitalBlackandWhiteThePrint@yahoogroups.com, Jeff Medkeff
<medkeff@g...> wrote:
> Joe Davajon wrote:
> 
> 
> > since Wilhelm's tests are based on fluorescent lighting, they in no
> > way reflect accurately what we can expect for print life for our
> > prints which are exposed to daylight which is much stronger lighting.
> 
> 
WIR test rating do not contitute ratings in term of absolute years of
display.

Here's what WIR has to say about it's own test procedure:

"What WIR had brought to the market is a standardized test procedure
for years of display for noticable color fading or color shift across
product lines.

There is an analogy between WIR's test procedure and the miles per
gallon rating used by the automobile industry: a true apples to apples
comparison."  

We should not take at face value WIR's permanence ratings anymore than
we take the mpg ratings of the auto industry. Each is designed to
serve as a basis for comparison.

The key word here is comparison, not absolute years.

Cheers,
André

Joe,

A print exposed in a room to 'daylight' isn't usually exposed to daylight, 
unless all your windows are open. It's been filtered through a window 
usually, a sheet of glass that removes most of the damaging UV. To expose a 
print to daylight, you have to take it out-of-doors, which is not a normal 
habitat of photographs.

Indoors, prints are exposed to glass-filtered daylight, incandescent lights, 
fluorescent lights, halogen lights, etc.

----- Original Message ----- 

Joe Davajon wrote:

> since Wilhelm's tests are based on fluorescent lighting, they in no
> way reflect accurately what we can expect for print life for our
> prints which are exposed to daylight which is much stronger lighting.

Folks, my point in making the initial post about the results on the 
Livick website was simply to point out to everyone that there are 
different ways to look at print permanence. I for one had mistakenly 
taken the Wilhelm years at face value and hadn't considered 
overcoating my prints to increase their expected lifetime. Why should 
I since the expected lifetimes reported by Wilhelm for ultrachrome 
inks were "long enough for me" already. What the Livick website 
suggested to me was that I need to rethink that position and take a 
more proactive approach. Both Livick and Wilhelm's data suggest that 
overcoating prints increases print lifetime. This could be partly due 
to UV filtering and partly due to the chemistry of particles that are 
suspended in a solid varnish where they are no longer at the air 
interface.

I am a scientist and I know full well how hard it is to get 
experiments right. The literature is full of data that was accepted 
for years and later proved to be wrong. We have tossed around a lot 
of general ideas on this forum like: glass filters the hard 
ultraviolet light. True but it doesn't filter all of the ultraviolet 
light. (They do make special ultraviolet filtering glass for artwork 
don't they?) How important is the unfiltered ultraviolet light on our 
inks? What is the quantum yield for photochemical reaction as a 
function of wavelength? Well we don't know for sure. So it's hard to 
definitively answer the question. 

The bottom line for me is not who is right and who is wrong. I just 
don't think we know for sure! I take this as a wakeup call which 
tells me that I need to be doing all I can to increase the longevity 
of my prints. Others on this forum have already done that but I have 
been lazy. Now I am much more concerned about using the right 
materials, paying more attention to overcoating prints, and doing my 
own testing.