Terry, I think that depends on the paper. Some do better with no added
size. In fact with heavier gum in proportion of 2 parts gum to one part
dichromate, I find no added size works better on all but the most
absorbent papers.
> gum at 17
> Baume . The cheapest way to buy it is in the form of white gum arabic powder
> from art print materials suppliers. You mix it 50/50 with cold water and let it
> stand to dissolve, in other words do not stir it. Here it costs about eight
> pounds per half kilo i.e. sixteen pounds a litre for the gum. You will need to
> keep it in the fridge.
Why not add a few drops of formaldehyde (maybe gloxal works too) or
thymol? My home-mixed gum is a year old and still fine with formaldehyde
added. (If someone is going to say formaldehyde in that amount is
dangerous, they better go out & sleep on the grass because your permanent
press sheets have probably been treated with it.)
I'm wondering tho what (was it Francois?) meant by "higher quality gum
arabic" being glossier. There may be a confusion here between a heavier
gum (the baume) and a more colorless gum, water white, as they say, which
the Winsor Newton is (don't know the baume). In my experience, a gum can
look quite amber-colored in the jar, but with pigment added it's all the
same. Tho I'll add that I've seen some *really* dark gum (including that
sold by the pint at Pearl Paint!) deserved only to be thrown out.
Judy