[alt-photo] A PVA postscript

[Henry Rattle]

My first, reasonably successful, trials of PVA as a size for tricolour gum
were carried out on paper which had not been preshrunk. Not a good idea, as
it turns out. Moving on to using Gamblin PVA at 1+1 dilution for prints on
preshrunk paper, I find that while Fabriano Artistico (cold-press,
traditional white) still works reasonably well, my favourite Saunders
Waterford HP reacts badly. After preshrinking under mild conditions (1 hour
in water at 25C) first gum (yellow) coat seems to work OK, but the
subsequent (magenta) coat is horribly blotchy and clears very badly and
unevenly. Looks as though internal sizing has washed out so that the PVA
doesn't go on evenly. A control with gelatin sizing looks fine with the same
coating and treatment.

Wonderful stuff, gum - just one variable after another...

Best wishes

Henry