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 18:26:41 2005