U of S | Mailing List Archive | alt-photo-process-l | Re: humidity and gum coating

Re: humidity and gum coating



On Sep 4, 2006, at 11:16 AM, John Brewer wrote:


For one thing, it seems to me that dampening the paper would be a perfect way to prepare for selective coloring, where you only want to color part of the picture, as in when people make a color picture from a black and white negative. I haven't tried this yet but might today.


Katharine, could you explain why this would be better than, say, masking an area with card when wanting to selectively colour?

Sorry, I haven't got back to trying this, but I'll answer the question anyway, since I'm not sure when I will get back to it.

This is probably one of those "six dozen of one, half a dozen dozen of the other" kind of things, if you use a mask while coating. I was thinking that with the pre-wet paper, the coating would sink in a bit rather than sitting up on the surface and so would be easier to contain within a prescribed area. But when I said that, I was thinking of coating without a mask. I've found that when I want to coat an area for selective coloring (without a mask, and with dry paper) if I whisk the coating with a dry brush, as one ordinarily would, then I run the risk of carrying the coating outside the area I want to coat, but you're right; a mask would solve that to some extent. The potential problem I see with that is that when you're setting the coating with a dry brush, you could risk picking up wet coating off the acetate of the mask and spoiling the drying coating with the wetter stuff. What I've done in the past (not that I have a great deal of experience with selective coating; I've only done this a few times) when I want to selectively color a small area, is use a drier brush to coat with (wick some of the liquid off the brush onto a paper towel before coating) so that the coating is less liquid and stays put. Like I say, it's one of those things you can approach several different ways.

Katharine







----- Original Message ----- From: "Katharine Thayer" <kthayer@pacifier.com>
To: <alt-photo-process-l@usask.ca>
Sent: Monday, September 04, 2006 6:17 PM
Subject: Re: humidity and gum coating




On Sep 3, 2006, at 8:34 AM, Venkatram Iyer wrote:



Dunking rather than soaking the paper, then hanging to drip, blotting it, followed by coating may be a way to prevent the inner fibers from getting wet.


I'm still playing with this wet-coating thing; I've gotten fascinated with it. even though the humidity is back to its usual 90+ % and I'm not having any more trouble coating as I was the other day when it dropped to 17%.

For one thing, it seems to me that dampening the paper would be a perfect way to prepare for selective coloring, where you only want to color part of the picture, as in when people make a color picture from a black and white negative. I haven't tried this yet but might today.

Yesterday I got to thinking that if this works, why couldn't you print the next layer of a multiple print as soon as the gum layer is dried, even though the paper is wet through---would save a lot of time waiting for paper to dry between layers. So I tried this, but had too many variables floating around to draw a conclusion even for this one print. For one thing, I used lukewarm water for the soaking, because the instructions someone sent me called for that, but I think I won't do that again, but just use the same cold water I use for development. And the brush had a lot of water in it because it had just been washed out, and for whatever reason it hadn't been squeezed out damp-dry as I usually do after washing it (maybe the phone range or something). So the coating went on really watery and sloshy. I'll do it again using cold water for the soak and making sure there's no extra water in the brush. But I also think the paper should be dried slightly; this paper was so limp when it was coated that when I picked it up, it hung off both sides of my hand like a dishrag. So I think Rajul is probably right that less soaking is probably better than more.

At any rate, following that protocol, I got a little bit of staining, but not very noticeable, and I'll try it again with modifications to see if I still get stain. Like I say, the stain is hardly noticeable and I'm thinking I may go ahead and frame this print (although I might mat over the smudges against the far right margin of the print) because I like how it captures the atmosphere of the day. I added this print to the wet-coating page, for whatever it's worth:

http://www.pacifier.com/~kthayer/html/wetcoat.html

This is also a good demonstration of how one can make a fairly realistic color print with two complementary color layers, if the scene is essentially a two-color scene (two colors plus grey). I brought the idea with me from painting, where I've made a lot of paintings using only burnt umber and blue.

I have a feeling I won't be done with this until I try printing a tricolor gum with all the layers printed on wet paper.
Katharine




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