U of S | Mailing List Archive | alt-photo-process-l | Re: gum print on glass

Re: gum print on glass

Bon Ami is always the first step in my glass preparation, followed by a good rinse and then flooding with high-proof alcohol. The issue isn't that the glass isn't clean; the issue is that, as Marek rightly states, gum doesn't tend to stick to glass without some sort of sub, be the glass ever so clean. I have my own sub that works very well for hanging onto the gum (fine pumice in acrylic medium) but it clouds the transparency of the image on the glass, which is why I'm always looking around for something else. But silane, which I tried before the thing I'm using now, just didn't work for me, and I had a show coming up and couldn't spend any more time messing around with it.

On Aug 28, 2007, at 5:58 PM, Erie Patsellis wrote:

Katharine Thayer wrote:

Thanks, Marek. I've tried that; for whatever reason it never worked very well for me. Glad it works for you.

On Aug 28, 2007, at 3:10 PM, Marek Matusz wrote:

It was 3-amonipropyltriethoxysilane. I am not sure about the origin of the sample as I had a solution of it that I got somewhere. I think this might be the same stuff that B&S sells. It takes very, very little to treat the glass.

> Date: Tue, 28 Aug 2007 11:42:16 -0700
> From: kthayer@pacifier.com
> Subject: Re: gum print on glass
> To: alt-photo-process-l@usask.ca
> Excellent, Marek; thanks for report; it makes me want to get back to
> my experiments with that
> The back-exposed print on glass that I reported most recently was
> done with no sub and stuck very well, but it was so overexposed (due
> to double dose of dichromate without adjusting exposure) that it
> needed some forced development to bring the image out, and I got
> impatient with brushing it gently with a soft brush and picked up a
> much stiffer brush and used it too aggressively and scrubbed the
> emulsion right off the glass. A subsequent trial was a complete
> failure; the gum didn't stick to the glass at all.
> If you don't mind my asking, what's the silicone material you're
> using for a sub?
> Katharine
> On Aug 28, 2007, at 11:18 AM, Marek Matusz wrote:
> >
> >
> > All,
> > I was finaly able do do some gum printing on glass with back
> > exposure. First of all gum does not stick on glass in my practice,
> > so I took advice from some earlier suggestions and looked for the
> > silicone subbing agent that I had for a while but never used on
> > anything. After I subbed the glass I just poured gum/pigment
> > dichromate mixture on the plate and let it dry. I poured a very
> > thick layer, totally opaque to the transmitted light. It took
> > several hours to dry and it is a big hassle since it needs to stay
> > levelled for a long time (and in the dark). I exposed through the
> > back of the glass in full sun for 1 to 2 minutes. These were faily
> > dense negatives and by no means optimised for the process. I could
> > likely make decent palladium prints with these. The development was
> > nice to follow and fairly quick as gum starting to dissove from the
> > top revealing image underneath. This felt and worked exactly like
> > carbon printing. The tonality of the imafe is excellent with no
> > graininess. The image sticks to the subbed glass quite nicely as
> > well. No problems with flaking or loosing parts of it. I am now
> > experimenting with carbon on glass with back exposure. Stay tuned.
> > Marek
> >
> > See what you’re getting into…before you go there See it!

New home for Mom, no cleanup required. All starts here.

Out of curiosity, has anyone tried aggresively cleaning glass, a la Bon Ami (an old gilders trick) to get it absolutely clean, in the past I have always had issues with gelatin sizing not sticking to glass unless I scrubbed it very aggressively (it won't scratch the glass).

Alas, no call for window or door gilding these days, and I'm not that old to be feeling like an old-timer.