I do not think that there is disagreement here ust different effects of
different practices.
Judy you say:
"There was a comment yesterday -- which I lost in the welter of Sense and
Sensitivity messages -- that once a gum print dries it would have to be
resoaked for about a year to soften the emulsion. Fortunately, this is not the
case. "
But when I have finished making my gum print using dichromate strengths that
will set hard on completion, I treat it in such a way as to make it archival and
this includes soaking it water.
When I have developed the last coat I dry the print and then expose briefly to
light until I see the change that this gives and this fixes the image. I the
leach/wash the print for six hours until the colours have returned to the colour
of my trial swatches. The print is then hung in the light to dry. As an archival
test for this approach I left a print under a camelia in the garden over the
winter. It got rained on,snowed on, walked on and received various other
unpleasant ministrations. When the camelis had finished its spring bloom I
washed the print under the kitchen tap. The print was as good as new. If I had
wanted to do something else to it i would not have treated to this 'archival'
processing.
"The proportion of dichromate is a
significant variable, as is the length of exposure, but in the olden days
it was common practice to work a print after drying and resoaking, or even
just rewetting. Or simply gently abrading the dry coat. "
That could be the case with weak sensitisers.
"Removing extra emulsion from a print in "automatic" (or ostensibly
automatic) development without leaving a demolition site behind is
difficult to impossible, because the emulsion is *extremely* delicate
before it has dried and the lightest touch can destroy all "photographic
quality." (That is if it's been exposed lightly enough for automatic
development.) "
But with the right combination of exposure and sensitiser the gum should be hard
enough to achieve the same effects as 'automatic' development with brush or
other forms of mechanical development.
As to bubbles leaving uncleared patches, this is a good indicator of how
effective water is as a clearing agent, I put a line of pennies, seven on large
prints, arranged down the middle of the back of the print with wider spacing
towards one end so that the print floats face down with a gradient in all
directions so that bubbles cannot gather.
"However, if you use the currently popular one part gum to two parts
ammonium dichromate formula, your emulsion may well be much harder when
dry."
That is a waste of dichromate and it reduces the strength of piment in the coat.
Why do people do it?
Terry