Re: gum slide

In a message dated 11/4/06 7:04:45 am, jseigel@panix.com writes:

> There are 3 or 4 reasons I could think of offhand for images to "slide off
> the paper" -- from too slick or resistant sizing (my experience, BTW, with
> gloy) to underexposure, or overly thick emulsion. There could be others,
> none requiring hardening from top (tho obviously you only need one).
>
> But I also think of the relief you see in a wet gum print, especially in
> the shadows. It disappears as the gum shrinks when dry, tho at first is
> quite 3-dimensional. (I notice it especially because my draining rack is
> at eye level.)  Is it tougher at the top or the bottom?  Or even
> throughout ?
>
> J.
>
Hello Judy

But surely the point is to get the relationship between the amount of gum and
dichromate,and the exposure and the pigmentation right. If the exposure is
too short in relation to the level of pigment, the light will not be able to
get down through the combined gum and pigment to bind the bottom of the layer
to the layer below or the paper. This is, in itself, a demonstration that the
effect is top down. This applies just as much to gums derived from acacia trees
as it does to gums produced artificially.

There may well be other reasons for images to slide off the paper, as you say
by applying too much size, but these do not affect the principle.

As you say, there is an excitement at looking at the three dimensionality of
a gum print either when wet or more subtly after it has dried when the
relationships between thicknesses of pigemented gum appear to correspond to the
distances in the view we percived when taking the picture. A kind of
hyper-reality (I think I prefer the hyphen).

I will be announcing my new programme of workshops covering multi-colour gum
and cyanotype rex and chrysotype rex very soon. The pdf for the cyanotype rex
will be available after Easter. I will be giving workshops on all three
processes in Pittsburgh next year.

Incidentally Mike Ware has a long article on gold processes in the current
edition of The History of Photography where he makes no mention of the
revolutionary research by Mike Maunder and myself, but that is hardly surprising .

Terry
Received on Tue Apr 11 02:46:20 2006