Re: Gum transfer

Sandy,
I tried your suggestion, but the gum image did not want to stick to the
gelatine layer of the paper, so I placed the sandwich on a piece of glass
with the photographic paper on top and rolled it several times and just left
it overnight. This way the whole thing would dry through the paper layer. I
peeled it off the glass this morning, I don't think my glass was all that
clean since some of the paper just tore off, but to my surprize the plasic
and the gum image was stuck to the photographic paper base. I peeled the
plastic off and to my absolute astonishment I found the image transfered to
the paper. Uneven edges from the coating, lots of pinholes, etc.
There was no time to scan the image this morning (and I am hoping to spend a
few days in Big Bend later this week). The only piece of photographic paper
that I had was from the lumen print experiments, not quite clean, white
background, so it is not a decent print, but a huge success in terms of
direction in experimentation.
Sandy, thanks for a great advice.
Marek, Houston

>From: Sandy King <sanking@clemson.edu>
>Reply-To: alt-photo-process-l@usask.ca
>To: alt-photo-process-l@usask.ca
>Subject: Re: Gum transfer
>Date: Mon, 17 Apr 2006 16:55:11 -0400
>
>Marek,
>
>The principle is that you leave the sandwich under pressure for a half hour
>or so for the gum and gelatin to stick together. Then hang to dry. If your
>gum image is on plastic you must use a fiber photo paper, otherwise the
>sandwich will never dry.
>
>Sandy
>
>
>>Sandy,
>>I assume this is for the developed image on plasitc to be transferred to
>>another support. Is a fiber based photo paper the way to go? Should the
>>drying be done under pressure? I guess I have to read some literature on
>>carbon double transfer. It always seemd so complicated I aways skipped
>>that chapter.
>>Marek
>>
>>>From: Sandy King <sanking@CLEMSON.EDU>
>>>Reply-To: alt-photo-process-l@usask.ca
>>>To: alt-photo-process-l@usask.ca
>>>Subject: Re: Gum transfer
>>>Date: Mon, 17 Apr 2006 14:11:15 -0400
>>>
>>>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 Tue Apr 18 07:53:16 2006