Gum Substrate

TERRY KING (101522.2625@compuserve.com)
07 Mar 96 09:00:33 EST

Richard Sullivan writes:

The substrate not only aids in stabilising the paper for registration but it
allows for forced air drying with a hair dryer. Ordinary unsubstrated paper
will buckle, curl and puddle, resulting in an uneven splotched development
if a hair dryer is used.

>My own experience is that with paper of the right weight and the use of pins
and magic tape, the paper should remain laterally stable. It will not buckle,
curl or puddle. My advice is that one should never use a hair dryer as the
stream of heated air is too localised. I use a fan heater. But I have seen
Peter Frederick use a hair dryer without any difficulty.

Are we talking of drying the paper after development or drying the dichromated
gum and pigment before exposure. If the latter, drying of the gum with a hair
dryer will lead to uneven insolubilisation before exposure and thus blotched
development. It is possible to dry the gum at this stage with a fan heater but I
do not recommend it. I let it dry naturally.

Richard continues:

Forced air drying allows one to halt the
development of a short exposure and short developed print without which the
image would just "slide" off the print if just hung up to dry.

> Yes. That is why I dry with a fan heater and I have done so for decades but
without a substrate. Over about the last ten years I have used a different
technique. I found that if one makes the first exposure long enough, the print
stays on the paper without the need for forced air drying. This is also true for
subsequent coats. The use of Gloy helps. Of course I use the fan heater to dry
if I am sizing between coats to harden the surface for the sizing brush. I know
that in practice,without the sizing, the only reason for forced air drying is to
hasten the time when one can apply the next coat.

Richard continues

No way could this have been accomplished with unstabilized paper.

> I do it every day.

And so do my students and ex students who now run commercial studios doing it..
One student has exhibited gum prints, made to this method, in Albuquerque.

A substrate is not necessary; it is an over complication. If people feel happier
using a substrate, then fair enough.

I would not have been saying that one does not need a substrate in such certain
terms on this list if I did not have large amounts of evidence and decades of
experience to back up what I have said.

I have spent those decades trying to make the process simpler for myself and my
students so that we can concentrate on the picture not the process.

BTW it is possible to obtain a good range of tones in a gum print with subtle
gradations of colour and tone with good detail with only three exposures.

As I did with Judy, I would love to discuss the matter over the work itself.
Discussions without the evidence can be a bit fruitless.

Terry King