I agree the hake brushes are terrible –
depositing hairs as well as having no feel to them. (They are useful for brush
development in cold water though.) I use [for 8x10 prints] a 2” watercolour ‘resable’
brush – not expensive but I’ve been using the same brush for over a year now
(maybe 100+ prints) and its never lost a hair [unlike me] and still has plenty
of spring to it [er … also unlike me].
Coating is a fun game. I never use a dry smoothing
brush – when I tried it made things much worse.
I print with gum or PVAL. They have
different characteristics and require different techniques – as will gum with
different amounts of dichromate. Gum and equal amounts of 13% dichromate is a wet
and runny liquid which I find goes smoothly and easily onto dry paper. PVAL and
equal amount of 5% dichromate has similar printing times but is a much more
viscous liquid. Tricks I have found useful are (1) wetting the brush (but
removing excess water) before use, (2) dampening the paper – helpful for more
viscous mixes, (3) using a softer watercolour brush for more liquid mixes, (4) allow
the gum print to self-heal – repeated thin coats hide a lot of unevenness in a
single coat.
Coating also seems to vary according to
the layer you are putting on: a first layer of yellow/sienna is always
perfectly smooth but intermediate layers of heavier pigments can be more
problematic.
Incidentally I print from a single
negative: if you’re trying to do 3-colour separation prints in a similar number
of layers then you’re problems are greater.
Geoff
Chaplin
ジェフ チャップリン
geoff@geoffgallery.net
www.geoffgallery.net
Skype: geoffchaplin1611
UK mobile (英国の携帯電話): +44(0) 7770 787069
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From: Paul Viapiano
[mailto:viapiano@pacbell.net]
Sent: 04 July 2009 15:36
To: alt-photo-process-l@usask.ca
Subject: a few notes on my first
few gum prints...
First of all, thanks for all the suggestions and comments on
my first tricolor gum. It was definitely a good learning experience for me.
There are a few things that I noticed while working that I
hope to clear up and solve.
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.
I know that the gum coating should be on the thin side, and
my guess is that for a 4x5 print I should be using approx .5 - .75 ml of
solution, but those hake brushes are horrible, very hard to get an even
coating, at least consistently for me.
I'm very tempted to try a synthetic watercolor wash brush as
I use for pt/pd (DaVinci Cosmotop). Expensive, yes, but the perfect brush for
pt/pd. Just a dip in distilled water, a shake or two, and it's good to go. I
bet it would really make for a nice smooth, even and just-right gum coating
using the same technique.
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.
Today was a disaster...I started on another tricolor print
and upped the ratio of pigment to gum, to get darker colors and it all devolved
from there. It happens, I'm experimenting...this has all been seat-of-my-pants
stuff but now I need to do a few test strips with a consistent pigment/gum
ratio to get a good starting point and figure out the smooth coat/non-grainy
stuff, too.
Comments and criticisms are most welcome. I'll report back,
if y'all don't mind, on my progress and findings...
Happy 4th to everyone here in the US and much thanks to all who
weighed in from around the globe as well...