U of S | Mailing List Archive | alt-photo-process-l | Re: Newbie Gum fun!

Re: Newbie Gum fun!

Jacek - I use lump gum, labelled Kardofan Gum. Mine comes from a colour
supplier called Cornelissen in London. It's straight from the tree, with
lots of bits and pieces in it, even the odd insect. It dissolves completely
in 24 hours or so at room temperature with the occasional shake. I then
filter (more properly, strain) it through two layers of a household cleaning
cloth - in the UK they are called J-cloths, kind of thin tough
artificial-fibre cloths usually with coloured stripes. It comes through
quite easily (well, over half an hour or so) and remarkably clear. Then I
add a couple of drops of formalin solution as a preservative. The resulting
gum solution is very pale in colour, fairly viscous (at the same 35g/100 ml
that you are using) and in my experience it washes off the print during
development more quickly and with more subtle contrast than the dark
lithographer's gum.

An oddity - I needed some formalin solution locally, and discovered a supply
in a local aquarium supplier - apparently used as an anti-fungal for fish.
Very over-priced, but handy at the time.

By the way, note the "in my experience" above - gum is a very personal
medium and everybody will tell you something just a little bit different!

Best wishes


On 16/4/07 09:16, "Jacek" <gonsaj@iinet.net.au> wrote:

> Hi all,
> I've just had my go with coating a pad of Arches Smooth paper 300gsm
> 100%cotton, I sized one piece in hot water first(no gelatin), but as I did
> this, I started getting speckled dots around a mm, which were lighter than the
> paper, they covered 3/4 of the paper?  I tried another piece of paper with a
> hot gelatin solution(no hot water sizing at all) and put it in the tray, where
> I got the same result of speckled mm dots?!
> I've tried using a Rough Fabriano Artistico paper with both the hot water and
> gelatin sizing, no problems at all there.
> Anyhow I hung the Arches to dry last night, I havent as yet checked the paper
> this morning. 
> Perhaps there is an issue with the Arches paper and I should take it back to
> the seller?
> I have bought the powder form of Gum Arabic, its a straw yellow.
> I tried two methods, to make a 35% solution in 100ml (35g of gum).
> The first method was to use a coffee filter and put 35g of that in there and
> poured distilled water to make 100ml out of it. There was one big gooey mess
> in the filter. Which I threw away once I got my 100ml.
> The other method was to put the gum 35g in 100ml of water, when I did this I
> thought there was no way the gooey mess will actually dissapear, but as an
> hour or so progressed it started slowly disappearing! :) I'll check on it
> tonight, and might pass that 100ml through a coffee filter to see if any
> sediment is caught and throw that away.
> What methods do you use to make a solution of gum arabic from powder?
> Many thanks
> Jacek Gonsalves