Digital BW, The Print

Steve,
 
> Does anyone know the pros and cons of using protectants such as PremierArt
> Print Shield, Krylon Preserve It!, Clear Shield and other such products?
> 
> To what extent, if any, do they actually preserve a print?
> How do they change the appearance?
> What are you guys and gals using?
> 

My fade tests, consistent with Wilhelm's, show that PremierArt Print Shield
increases the pigments' resistance to fading.  In one of my tests the MIS UT
pigment's that were sprayed faded about 10% slower, and the UC pigments
faded about 30% slower (bringing them almost up to the MIS standards).

The coatings without UV blockers in them (like Lascaux) have been, at best,
neutral in my fade testing.  Between the lines, it looks like Wilhelm's
results may indicate that the coatings add some degree of protection by
slowing the rate of oxidation.  This is what I'd expect in theory, but my
"initial" (relatively short) fade tests have not found that.

All the coatings I've used increased glossy paper dmax and reduce matte
paper dmax.  Lascaux reduces matte paper dmax the most and is what I use on
matte papers.  Three light coats offer some protection against abrasion with
no significant appearance alteration.

Many, particularly older coatings yellow with age or otherwise have negative
results.  I, therefore, don't trust coatings unless they have been used for
years or have been tested by someone I trust.  PremierArt Print Shield and
Lascaux (the well known Rohm & Haas B72 formula) fit into this category and
are what I use.

The quality of the nozzle is an important factor.  Many sprays just do not
go on evenly.

The water-borne coatings are hard to apply smoothly, tend to get dust in
them due to slow drying, tend to remain tacky for a very long time, and
alter the appearance of the print across most of the grayscale ramp.  (As
such, they need their own profiles.)  I don't use them.

Hope this helps.

Paul
www.PaulRoark.com