Re: Tiny Bubbles In The ... Gum

I don't think it's contaminated paper if that's what you're getting at. I
thought maybe foam brushes might cause this because of the rough bubbly edge
surface. I'm wondering if the paper is releasing air because its dry. My
paper has not been pre-shrunk or sized in any way. I switched to a hair
brush but it didn't seem to make much difference. I don't want to "work" the
paper too hard because I'm afraid of roughing it up. I've read that most
people lay down a quick coat and then smooth it out. I'm having problems
with the smoothing out part it just seems to make things worse. I'll avoid
wasting any energy double coating, thanks for the tip. If my mix has low
visocity could that cause it? ie too runny?

~m
----- Original Message -----
From: "Katharine Thayer" <kthayer@pacifier.com>
To: <alt-photo-process-l@sask.usask.ca>
Sent: Sunday, August 28, 2005 12:31 PM
Subject: Re: Tiny Bubbles In The ... Gum

> Hi Michael,
> Do you mean bubbles in the emulsion? or that the the coating beads up on
> the paper leaving little open spots as you brush it on? I haven't seen
> the former, but the latter can be a function of a too-heavy coating of
> sizing.
>
> Double-coating wouldn't be advised for gum, since dried gum is
> hypersoluble; brushing wet gum over dried gum will just re-dissolve the
> dried gum and mess up the coating. Somewhere in the catacombs on my site
> I've got an example of this and could probably find it for you if you
> were interested in seeing it.
>
> Katharine Thayer
>
>
> Michael Koch-Schulte wrote:
> >
> > I've just done my first gum prints (yes yes I can hear it...the golf
clap).
> > Despite my worst efforts I actually obtained results that were not too
bad.
> > A few things have been bothering me though. I was getting quite a bit of
> > bubbling in the emulsion as I brushed it on, my coating settled down a
bit
> > but the unevenness was apparent to me afterword. Is there something I
can do
> > or add to my emulsion to counteract this? Is it my brushing technique?
My
> > brush? I tried using both a foam brush and a hog's hair brush, they seem
> > about equal. Using a coating rod was pointless I noticed. Also, for a
> > "one-coat" print, generally, how much emulsion should I be using for an
8X10
> > print? My starting mix was 6 ml or Gum, 6 ml Potassium Dichromate and
about
> > 2 grams of pigment. My estimation is that I used about 7 or 8 mls on my
> > first 8X10 print. Too heavy? How do I determine a saturation point for
my
> > paper (Rives BFK). Do people double coat gum?
> >
> > ~m
Received on Sun Aug 28 19:55:49 2005