Digital BW, The Print

John,

>... I am considering a trial of Lascaux for my monochrome prints. 
>Does anyone have any permanence data about this spray, or if there 
>is any chance it may yellow or change color over the long haul? ...

B72 is very well know in the conservation field, and seems to be trusted to
be archival and non-yellowing.  I have read that the Tate has used in on old
masters to protect them.

Ross Merrill, Chief of Conservation at the National Gallery of Art,
Washington D.C. (USA), in a 1997 speech regarding pastel conservation said
as follows regarding fixatives:

"Today there are a number of alternatives. Krylon Acrylic Varnish B72 is
used by conservators. This product will remain unchanged for 400 years, but
does have a tendency to saturate the surface. Grumbacher B77 varnish or
"tough film" is the same as B72, but will not saturate. Krylon workable
fixative and Sennelier fixative are both good products. One should stay away
from Grumbacher's "blue label" fixative." See
<http://www.bmi.net/knapp/iapsmerrill.html>

Lascaux Fixativ is B72.  See
http://www.lascaux.ch/english/restauro/pdf/7103_02.pdf  This is the only B72
aerosol spray I know of.  Krylon no longer makes the B72 formula spray.

I used the Grumbacher Tuffilm for a while, but the nozzle is not as good as
the Lascaux nozzle.

Hope this helps.

Paul
www.PaulRoark.com