Digital BW, The Print

Further to my earlier post I like to quote statements from Mr. Livick:
      "FLUORESCENT LIGHTING IS VERY SLOW, IN FACT FEEBLE AND ARTHRITIC WHEN IT COMES TO 
FADING PIGMENTED INKS. CONSEQUENTLY ANY FADE TESTING ORGANIZATION WHICH IS WORKING USING 
FLUORESCENT LIGHTING AS THEIR MAIN SOURCE OF ILLUMINATION, IS NOT ACTUALLY ACCOUNTING FOR 
THE MAJORITY OF PRINT DISPLAY CONDITIONS. EXTRAPOLATIONS WORKED OUT UNDER FLUORESCENT 
LIGHTING WILL YIELD RATINGS FOR EPSON'S LATEST ULTRACHROME INKS THAT ARE APPROXIMATELY 2/3 
HIGHER THAN NORMAL DAYLIGHT RATINGS. IF YOU MULTIPLY THOSE FLUORESCENT RATINGS BY .33% IT 
WILL REFLECT A MORE ACCURATE RATING FOR DAYLIGHT DISPLAY CONDITIONS WHEN USING ULTRACHROME 
TYPE OF INKS."


I Expected that Wilhelm labs would be testing using high energy fluorescents but my 
surprise they are not.  I made an assumption and I was wrong. Mr Livick is right.

Wilhelm  is using a 'friendly' test protocol originally developed by Kodak where even the 
exposures to cool light fluorescents are glass filtered.  In other words your prints 
better be under glass.

It too often occurs that when industry gets involved in designing test methods under the 
umbrella of other organizations,  the method is designed to make the products of the firm 
or firms that propound and sponsor the standard look good.  What you often get is a low 
common denominator so that everyone's products (the firms' involved in the committee) 
pass. A test method that resulted in longevity predictions of 10 years would not sell many 
printers or paper, would it?

According to other papers from Wilhelm, they use highly discriminating colorimetric 
methods to measure very faint changes in the prints accurately. In this way, although the 
light exposure is mild, the measurements are very discriminatory and by extrapolation they 
come to the numbers predicted for longevity.  It all seems to me a little bit manufacturer 
friendly, and why not, it is the manufacturers that pay for the service not the users.

I am coming to see that Mr. Livick did have some ground for his deprecation of the 
Wilhelm's predictions but I can't agree with either that a lumen is a lumen.  I have yet 
to see the exact specifications for the spectral characteristics of the light source and 
although they must exist they should have been included in the same paper as an appendix 
so the reader can readily verify that the light source is not manufacturer friendly too.

As for us users, what that tells us is that the prints better be on display under UV 
filtering glass or else Wilhelm's 70 years predicted longevity will result in the print 
becoming senile in its teens.

Julio Fernandez