Digital BW, The Print

John,

> 
>  ...... As to the varnishes -- they've mostly yellowed and cracked,
> > historically.
> >
> > Paul
> > www.PaulRoark.com
> 
> 
> That is very true over the very long term (as in Rembrant and
> Leonardo) but none of these were acrylic varnishes that can stretch
> and adapt to changes in temperature and humidity.


I agree that acrylic seems to be the class of materials that, at least
initially, has appeared to be the most stable.  The Lascaux Fixativ, which I
favor for matte papers, is said to be pure Rohm & Haas B72 formula.  It has
actually been used as a benchmark for archival materials in the conservation
industry, according to some of my reading.

> I still think there is a lot of good reseach to be done there.

Indeed.  Ultimately, I think the R&D that is going into tough, clear,
non-yellowing coatings -- for cars and all sorts of huge industries -- will
give us virtually bullet-proof images.  (The initial carbon nano-tube
fabrics are, apparently, clear -- as well as being stronger that about any
other substance.)

> As to the yellowing, now that is a concern. 
> Most all of these new coatings all claim to be
> "non-yellowing", but ...

And it could be a major one.  The companies need to provide information
relating to tests, reputation from experience, or other evidence that people
will feel comfortable with.  Too bad that's costly.  Luckily for them and us
the internet can provide at least more and faster information than has been
available in the past. 

Paul
www.PaulRoark.com