U of S | Mailing List Archive | alt-photo-process-l | Re: a few notes on my first few gum prints...

Re: a few notes on my first few gum prints...

On Sat, 4 Jul 2009, Loris Medici wrote:

.... a (relatively) nice quality flat foam brush (those with wooden handle and harder foam) is what I use for coating and it worked well for me since the start.
This is the only part of the coating discussion so far I recognize,
and tho I realize materials may be so different from different sources (what's a hake brush in my art store may be unlike anything ever seen in yours), not to mention the specific gravity of the mix and the personality of the paper & the coater, that we're never going to agree.
Still, I cite experience from having taken hundreds of space-cadet undergraduates through the process, on top of my own ability to screw up --- with certain findings and principles more or less constant.

[If memory serves, this is described in better detail on Alternative Photography.com, which has Post-Factory #1 complete. But for the record, here's the story more informally:

I probably have 15 kinds of hake brushes and never yet met one I'd apply emulsion with -- they're for smoothing (and generally better if you crop off the outer layers of hair, and run a bit of glue into the roots to hold the rest tight).

The emulsion itself is applied with a foam brush, about 3 inches wide is fine, tho wider for a huge print & smaller for a tiny one is helpful -- you wet it a bit then gently squeeze til it's just damp, not wet enough to dilute your mix, and not dry enough to suck up too much emulsion at one time. Not just any foam brush however ... when I bought mine, the ones with the (red) plastic handle were useless, the foam was too thin and stiff. The good ones, as Loris describes, were the ones with the wooden handles, but that foam was softer, not harder, and therefore it more easily applied an even coat (without edge ridges between strokes). I imagine there are many types, varying by store and locality, but IME the softer foam gives an evener, sweeter, easier coat.

Then the hake brush lightly flicked over that coat smooths it, the finishing touch.

Granted, all is subject to variation by materials, timing, technique and sunspots... but the 2 basic rules IME are that using hake brush to apply emulsion is doing things the (very) hard way-- and a good way to ruin an expensive hake. (For mere whisking, the cheap hake's are fine.)


I smooth the coating with a cheap synthetic brush (since it dries very fast with the aid of a hair dryer and is ready in a short time for the next print/coat) because some paints tend to coagulate (if you like; couldn't find a better description) and give a grainy look if I don't... I don't coat by numbers (e.g. 2.5 ml per 8x10") so using a foam brush (which absorbs a substantial amnt. of coating solution and is hard to control in that aspect) doesn't hurt.


On 04.Tem.2009, at 09:36, Paul Viapiano wrote:

One, is the use of hake brushes. I've been using the inexpensive variety found at the typical art store, about $2-4 each. Coating is difficult with these because there is absolutely no spring to them, they just go limp and the hair goes every which way even brushing lightly. I know how to coat pt/pd and am always successful when coating that emulsion. Gum, although more viscous than pt/pd should still flow on quite easily.
Here's something else...I notice that Sam Wang, in his gum article on Unblinking Eye, brushes on his gum coating and doesn't use another dry brush to smooth it. I'm thinking of trying this as well, as long as I can get a really smooth, even coat down with a good brush.

One of the things I noticed was that while burnishing my coating with a dry brush, it started getting very grainy looking. I'm thinking that I could keep the smoothness if I just brush on once, nice and thin, and don't use another brush to burnish and dry.