Digital BW, The Print

>... one of Wilhelm's ... supporters

Add me to that list.  It's so much better than nothing, as long as we know
the conditions of the tests and, for example, that the manufacturer decides
what tests get published -- thus no bad results.

> There was also talk that Henry helped Premier Art develop 
> this spray in the beginning. Maybe. 

And maybe there was a friendship or the like.  Perhaps the principals have
the same concerns for longevity and have been working together and with
other like minded people for a long time.

>... the not knowing if all these products are the same ...

I think same factory produces many of the canned sprays that use the same
can, but are made to different formulas and specifications.  I definitely
have tested different companies' sprays that were in the same type of can
and found them different. 

> or if Premiere Art has a superior formulation (or not). 
> There is absolutely no way to tell.

We can obtain some information just by easy fade testing.  I've done some
and found different fade rates and yellowing of some products.  With a
spectro you can detect these things with just a few hundred hours of
exposure.  

The very long term problems are almost impossible to test, however.  We see
a lot a fade testing because it is easy.  Long term accelerated age testing
is really crude in comparison.  So, here, I give more weight to history.
Most varnishes have yellowed.  That is the problem with almost anything with
a benzene ring in it -- UV breaks them and that causes the yellowing.  That
is how I ended up with the "aliphatic" (straight line instead of the usual
aromatic ring structure) polyurethane for my water-based coating
experiments.  Unfortunately, even aliphatic epoxy yellows.  Almost all of
the natural varnishes have the yellowing problem. (I'm not a chemist and
would appreciate any corrections to the above.) 

Acrylics (e.g., the Rohm & Haas B72 in Lascaux) have a great reputation for
non-yellowing as far as I can tell.

Even though my tests show no yellowing with Print Shield, I like to see a
Wilhelm test, as, for sure, will customers.

> ... Epson is committed to Premier Art 

Don't you think they are just a customer?  I think Premier Art developed the
UltraSmooth paper, but I believe PA is just one of many suppliers.  I
suspect Epson (and I) like working with Premier Imaging (aka Premier Art or
PA by me in profiles, for example) because we get good products and straight
talk from the people there.

>... there may very well be some liquid laminates ...
> give amazing results ...

I think so also.  Some of the coated matte prints are about the best I've
seen.  The carbon is embedded under a coating so that it's very well
protected from at least physical abrasion.  One of the highest dmax's I've
measured is from a (matte) print on Arches Hot Press (uncoated) that had a
water-based polyurethane coating on it.  (The rest of the test was a bust --
I couldn't deal with the tiny paper fibers sticking out of the image.)

Paul
www.PaulRoark.com