Interview with Henry Wilhelm on print permanence
 

Mr.T wrote:

"frederick" wrote in message
news:1178322277.137906@ftpsrv1...

Sure - I agree that because an ink/paper combination gets a 200 year DPR
from Wilhelm doesn't mean it will last 200 years on my dining room wall.
But you can be highly confident that it will last much longer than an
ink/paper combination rated at 10 years.


And that is where you may be mistaken. As others have pointed out already,
that would ONLY be the case IF the dominant mode of failure was under test,
or at least common to both cases. This CANNOT be assumed to always be so. In
fact the Epson case makes that quite obvious.

MrT.



I also think Epson do sponsor the Wilhelm tests.

rm

Interview with Henry Wilhelm on print permanence
 

All the manufacturers pay the Wilhelm Research Institute to conduct the
tests.

This has been a major credibility issue for many people, but then the
money has to come from somewhere.

Cheers,

Wayne

Wayne J. Cosshall
Publisher, The Digital ImageMaker, http://www.dimagemaker.com/
Blog http://www.digitalimagemakerworld.com/
Publisher, Experimental Digital Photography
http://www.experimentaldigitalphotography.com
Personal art site http://www.cosshall.com/



Rob wrote:
Mr.T wrote:

"frederick" wrote in message
news:1178322277.137906@ftpsrv1...

Sure - I agree that because an ink/paper combination gets a 200 year DPR
from Wilhelm doesn't mean it will last 200 years on my dining room wall.
But you can be highly confident that it will last much longer than an
ink/paper combination rated at 10 years.


And that is where you may be mistaken. As others have pointed out
already,
that would ONLY be the case IF the dominant mode of failure was under
test,
or at least common to both cases. This CANNOT be assumed to always be
so. In
fact the Epson case makes that quite obvious.

MrT.



I also think Epson do sponsor the Wilhelm tests.

rm

Interview with Henry Wilhelm on print permanence
 

Apart from the fact that I don't like the US centric nature of your
geographic sub parts :), I substantially agree. Where I disagree is
that, from a purely practical basis, it is very hard to multiply the
amount of testing like that. You just listed four for the US, and
presumably that is not all you would want. If you went this route we'd
need about 5 for Australia, 3 for Italy, probably 6 for Russia, etc.
Plus of course the natural light is very different in these different
locations, not just temperature, humidity, atmospheric particulates,
etc. Then there are the different types of artificial lighting in use,
plus greatly varying lighting levels.

A better route would be a small number of closely defined typical
climates, such as:
dry, hot
dry, cold
humid, hot
wet, cold
temperate
Air conditioned (perhaps at two different temperature/humidity targets)

Even this, I think is pushing the practicality of testing.

But certainly the standard should be published and defined tightly
enough that multiple labs can perform matching tests.

Cheers,

Wayne

Wayne J. Cosshall
Publisher, The Digital ImageMaker, http://www.dimagemaker.com/
Blog http://www.digitalimagemakerworld.com/
Publisher, Experimental Digital Photography
http://www.experimentaldigitalphotography.com
Personal art site http://www.cosshall.com/



Alan Browne wrote:
Wayne J. Cosshall wrote:
All the manufacturers pay the Wilhelm Research Institute to conduct
the tests.

This has been a major credibility issue for many people, but then the
money has to come from somewhere.

This is why a test standard and method has to be defined, accepted and
published that can be replicated in separate labs for similar results.

As others point out, it should be "general" purpose and reflect the
environments that people who buy most of the paper use.

It could have multiple parts (eg: Part A: Archival, Part B: Museum
display, Part C: home (sub i: North East US, ii: LA, iii: Phoenix, iv:
Miami, ...), Part D: ...).

Cheers,
Alan

Interview with Henry Wilhelm on print permanence
 

On May 7, 8:29 am, "Wayne J. Cosshall" wrote:
Apart from the fact that I don't like the US centric nature of your


Wayne: as you persist in top-posting, I won't reply.