Re: Gum hardening: top down experiment good image

I'd be happy to add this to my website, Marek, just send it to me as
a jpeg and (now that I have a better mail program than when I tried
to do this with Chris) I can just take it and upload it.
Katharine

On Apr 13, 2006, at 7:06 AM, Marek Matusz wrote:

>
> It took me two day to sort thing out a bit. I have repeated the
> experiments with the HP transparency coated on the emulsion side
> with the thick gum mixture. I tried exposure form the back from
> about 5 to 30 minuts and every time the result was the same. I
> could see the image developing, I would take it out of water and
> literally see it melting in front of me. Even lying flat. It looked
> like gelatine meting, kind of losing shape, becoming softer and
> ending up with a puddle of pigmented gum (remember the Indiana
> Jones movie?). After removing all the gum from the transparency I
> noticed a very nice tan image embeded in the transparency coating.
> Kind of like a very thin of pyro stain. All the details vere there
> if you held it to the ligh just so. So something was happening with
> htis transparency coating that was messing up with my experiments.
>
> Next logical thing was to put the gum on the uncoated side. I
> coated a couple sheets, exposed through the back They all developed
> by dissolving the unhardened gum from the top, revealing a
> continuous tome image beneath. The image was rather robust, with no
> tendency to flake, slide off or anything. Did I mention that on
> some of the sheets I removed the coating by soaking in chlorox and
> scrubbing with a brush.
>
> It is so amazing how easy it was to make a good image. My coating
> was very heavily pigmented and thick. I could barely see through it
> looking directly into a 50W light bulb.
> Same coating exposed from the front simply flaked away. Same
> emulsion coated on paper and exposed in the usual way for 15
> minutes mosty flaked off with a very contrasty result that did not
> resemble the original image to a great extent.
>
> I am really excited about making prints on glass and perhaps
> transfer to paper.
> I do not have a web page, but I scanned the transpareny in my flat
> bed scanner (not in the transparency mode, it is just a reflective
> scanner). Katharine maybe you can add it to you page or somebody
> else. I could put it on one of the free web site, but I will not
> have time to mess with it until the weekend.
>
> All this most likely does not relate to regular practice of gum
> printing wityh very thin layers, where I think enough light is
> passed through to harden the entire layer (pehaps a crosslinking is
> a better term) and then during the development phase wash away the
> gum and pigment in proportion to the crosslinking. Paper does
> interact as well and I see it soaking dichromate from the gum
> solution on the first coat, just like a lot of people have
> observed. Oddly enough this does not happen on subsequent coats if
> you do multicoat gums.
>
> Experimentation rules
> Marek, Houston
>
>
>
>> From: Katharine Thayer <kthayer@pacifier.com>
>> Reply-To: alt-photo-process-l@usask.ca
>> To: alt-photo-process-l@usask.ca
>> Subject: Re: Gum hardening: top down experiment
>> Date: Wed, 12 Apr 2006 17:05:21 -0700
>>
>> I don't know if anyone was planning to try this with Pictorico,
>> but just in case, let me report that I just used my last piece
>> of Pictorico for a quick experiment and I wouldn't recommend it,
>> for several reasons:
>>
>> (1) Pictorico goes sticky when it gets wet, so it's very difficult
>> to smooth out the coating; the sticky coating on the Pictorico
>> hangs onto the gum the way it was laid down with the first
>> stroke of the brush, and that's how it stays. You just can't move
>> the gum around on the surface.
>>
>> (2) the coating on the Pictorico hangs onto the dichromate, as
>> some paper/sizing combinations do, and the Pictorico will take on
>> a bright yellow cast that will have to be removed with
>> metabisulfite.
>>
>> (3) you can't dry it with a hair dryer. This may not be a problem
>> for those who don't usually use a hair dryer, but that's how I
>> always dry my gum layer, and the heat turns the Pictorico white.
>> This cleared to clear after a while, on the first drying, but on
>> the second drying (after treating with metabisulfite and rinsing
>> in water again) I found that the white didn't go away in some
>> places.
>>
>> Other than those few things, it really makes a great image.
>> Katharine
>>
>
>
>
Received on Thu Apr 13 08:33:49 2006