Digital BW, The Print

One of the best dmaxs I produced was with water-borne coating (Hydrocote
polyurethane) on Arches Hot Press (un-coated) paper.  It was not a perfect
print in many respects, but the point is that a matte paper with a coating
can give a very high dmax, which I assume is a lot like color gamut.

I found that a spray of solvent-based fixative before applying the
water-based coating helped the coating stick.  It also avoided the
occasional smear that I found with the water-based solutions.  (I was using
a "Mayer rod" to do the coating, but it did not scale up well.)  Like with
paints, the water-based tend to lay on top as opposed to going down into the
paper.  They are actually suspensions of, as one expert said, "gooey little
golf balls" of coating.  

I think one of the attractive aspects of the water-based coatings is that
they end up thicker than the solvent-based versions.  The depth of the clear
coating may be part of the look that can be so impressive.  That thickness
also appears to give more protection to the print.  I think the Wilhelm
tests of the Premier Art Eco Print Shield may indicate the UV protection is
also superior.

Helen, what type of rollers do you use?  Can you wash and re-use them?


Paul
www.PaulRoark.com