300 gsm papers often do not need stretching.
Gloy
For a first hardening coat you could try PVA which I was told is an acronym for
poly vinyl acetate or alcohol which is the basis of Gloy. Mix the PVA powder as
if it were powdered gum arabic, ie 50/50 with water. try that for size (sorry)
as it is seven years since I did it. Then mix the resulting gum 50/50 with a
strong solution of ammonium dichromate. Coat the paper and dry in the dark.
Expose until the colour changes slightly, then wash until the dichromate stain
is almost gone. Dry and put on first coat of dichromated gum and pigment.300 gsm
paper treated in this way should not need stretching. The whole preparation
processs should not take more than two or three hours.
We should send you an aid package ! but I am sure there must be a PVA based
office gum on the market in the US. Maybe Gloy is on sale in Canada.
I can send you a pack if you like.
I rarely stretch paper but if the paper is stuck down at the edges with brown
paper gummed strip available from 'artists colour men' and etching suppliers
and then lightly wetted with a brush on one surface only, the paper should
stretch and dry overnight or in a couple of hours depending on the ambient
humidity.
it is also possible, after the first coat, to size between coats with warm 2 or
3 % gelatine size
dried quickly. It must be warm and dried before it has time to gel. That would
cut out the two days hardening the gelatine. You need to be dealing here with a
paper that is both body sized and tub sized. That is why I suggest that people
start with Fabriano 5 NOT and Bockingford.
I hope that is helpful. Let me know if you have any success.
Terry.