Re: gum redevelopment

Keith,
     This is my limited experience--a last ditch method that doesn't produce
the best results. I had no budge with a water soak, and budge with ammonia
and friction and hot water in the shadows but not in the highlights, as
Demachy said. I am going to test a print today, printing another layer on
top with no added size, just to see if dimensions changed or sizing is no
longer reliable with the use of the ammonia (to reprint, you need to resize,
it is said).

If boiling water can be used on a dried gum print, that shows how hard it
is, once "old". I used to think that you couldn't dry mount a gum because
the press would be too hot, but I put a gum in at 200-250 for a couple
minutes to test this and nothing happened.

I wonder if the difference in effects is related to how much exposure the
layers received--multiple printing receiving even more--or how thick a layer
is--presuming a one coat "back in the day" was a thicker one. I should
really try a light one coat exposure, let the print sit for a week, and then
soak and see. I'm just thinking aloud here, no conclusions, but if it works
for Judy, and the gum printers who wrote years ago say so...I think the
mention came up 4 or 5 times in books, and even was recommended to partially
develop your prints, dry, and then redevelop later at your leisure. However,
most used it with an alkali (caustic potash, sodium carbonate, ammonia,
bleach, sodium bisulfite). Demachy was the first to contradict this
practice.
Chris

> Chris,
> I've never found it possible to redevelop a print with water, hot or cold,
> after it has dried. And believe me, I have tried.
> On the other hand, I do occasionally use ammonia and Clorox to whack away
at
> the gum on a dry print. The results vary, as you can imagine.
> Keith
Received on Thu Jul 8 07:56:56 2004