Re: Gum transfer

Marek,

Try the following and see what happens.

Take a piece of photographic paper and fix it out and allow to dry.
After it dries, soak it again in a alkaline solution of very hot
water for 15 minutes or so, then rinses briefly in warm fresh water.

Squeegee the gum print on plastic to the emulsion side of the photo
paper, leave under pressure for thirty minutes or so, then allow to
dry. Drying may take several hours. The image should either stay on
the plastic or transfer to the paper, or half and half which would be
the worst case scenario. This is the protocol for double transfer
carbon. May not work, but should be worth a try.

Sandy

>There were a lot of interesting posts this weekend and I am going
>thorugh them now. I have done a few more gum transfer experiments.
>Here are some observations and issues.
>
>When exposing a gum layer through the substrate (glass, polyester,
>etc). This is "expose through the bottom mode" heavy pigment
>concentration is OK, coating imperfections are not that critical as
>the air bulles rise to the top, streaks in coating are also on the
>top. A thin image layer that adheres well to the substrate after
>development shows relatively few imperfections and looks suprizingly
>good. I have not done much more on that as I am waiting for a sunny
>weekend where I can experiment with some gum on glass.
>
>Gum Transfer.
>Here is how I approached it. I though it would be very difficult to
>transfer actual developed and hardened gum image by means of
>softening it and transferring to the paper. Instead a process
>similar to a single carbon transfer was appealing to me. Here is
>what happened.
>
>I coated a few sheets of plyester with same emulsion (gum, lamp
>black, ammonium dichromate) that I used in my previous experiments
>(expose through the back). This time I exposed in a traditional way
>from the top. I will call it the gum tissue. This should form a
>hardened image on top of the gum layer with unexposed and soluble
>gum on the bottom. We know what happens when you put this image in
>water. Everything just slides off.
>OK, I then placed the gum tissue on top of gelatine sized paper,
>made a sanwich let it sit for a while and placed in warm water to
>start dissoliving unexposed gum so that the tissue and the support
>could be separated. Then just wait until the water dissolves the
>rest of the unexposed gum revealing the image.
>
>Some of the difficulties. Even a very short water immersion (cold or
>warm) of the exposed tissue to remove dichromate softens and starts
>dissolving the gum, no usable image can be transferred.
>
>The tissue image needs to have decent mechanical strength for the
>transfer. It needs to be thicker, which suggest less pigment,
>thicker coating.
>
>All the air bubbles and imperfection are on top, where the image is
>formed. There are all visible in the final image. Rollesrs and other
>means of smooting out the coat do not work with thick layers.
>
>My impression is that because the dichromate is present in the
>transfer process for about 30 minuts, before tissue is pulled away,
>I am getting a dark reaction, or something, as I am not getting very
>clean highlights. My exposure might be too long, or dichromate
>concentration too high as well.
>
>My negatives are for Pd printing, not for carbon. Just a minor issue.
>
>As Sandy noted I could print in carbon, but it is such a finicky
>process that requires a very precise time and temparature control..
>I am still hoping that an easy way of transfer could be found with
>gum, or perhaps gelatine/gum mix as I am thinking now.
>
>I have one picture from this trials and perhaps Katharine would be
>so kind to add it to her site.
>
>Marek, Houston
Received on Mon Apr 17 12:11:29 2006