Digital BW, The Print

On 10/14/02 8:26 PM, "Paul Roark" <paul.roark@...> wrote:

> Frankly, however, I think a water-based polyurethane might be a better
> choice.  The acrylic first layer is favored by conservators because at least
> the Golden version is removable -- in theory.  However, I don't think that
> factor is important in this application.  I see the coating as part of the
> product, not an after-thought that is applied just to protect the artwork.
> I think the polyurethane's superior toughness and resistance to humidity and
> chemicals may make it a better choice.
> 
> Varathane makes several water-based "Diamond Wood Finishes" (blue can at
> your local hardware) that appear to work very well -- no dilution needed.
> The "Outdoor" version has UV inhibitors that could be useful (in fade
> testing now).  However, I don't like much yellowing, and, like UV filters,
> these UV inhibitors are slightly yellow.  The Eclipse, however, is bright
> enough and blue enough that with one coat it stays bright and 0.01 units
> cool.
> 
> EAM just gets too yellow with the UV inhibitors.  So, to get rid of them
> with polyurethane, use Varathane "Interior."  This formula was made for
> maximum clarity.  With EAM the first coat remains almost a matte and the
> Dmax is only up to 1.72.  However, with a second coat EAM is a nice luster
> with up to 2.33 for the Dmax.

Stay clear of polyurethane--they yellow terribly.  Martin's varathane prints
turned completely yellow in about 6 months.

The water-based golden products are all 100% acrylic...absolutely no
polyurethanes.

Robert