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RE: sumi ink for gum



I attempted some preliminary tests using Sumi ink (Yasumoto & Co.), as the
coloring agent with gum bichromate and the results were interesting.  To
briefly review, I recently discussed problems I had experienced in printing
Kallitype over gum.  Kallitype, I thought, was necessary for my purposes, in
that it provided superior detail and dmax over the ivory black gum I was
using.  On Judy's suggestion, I used Sumi ink.

These tests used equal parts Daniel Smith gum arabic and saturated Potassium
Dichromate solution.  Paper is Fabriano Artistico and exposure was under a
black light bank.

Here's my step tablets:  http://199.179.174.243/steps.jpg


strip # 1:  Daniel Smith ivory black watercolor exposed for 6 minutes.  You
can see why I am looking for more dmax!
strip # 2   Sumi ink exposed for 3 minutes.
strip # 3   Sumi ink exposed for 10 minutes.
strip # 4 	Sumi ink exposed for 20 minutes.
strip # 5   half of the previous amount of Sumi ink mixed with half of the
amount of ivory black
	used in strip 1.  Exposed for 10 minutes.

Sumi ink used alone stains considerably.  Also, there is a strange phenomena
going on where the very lightest whites in the print pick up MORE stain than
some of the lighter grays.  This is seen in strips 2 and 3. This is not a
great scan, but you can still see the gradual progression from dark to
light, and then back to dark.   In strip 4, the staining problem has gone
away, but unfortunately the prints take far too long to clear (if they clear
at all, that is - I gave up).  #5 shows some promise.  Judy is correct - the
staining IS less, but its still a considerable problem.  Funny how on strip
# 4 the staining is gone, but an actual print I made refuses to clear.

One final observation: the staining seems to "creep" in halfway through the
development.  The light areas clear very rapidly - within a couple of
minutes the white areas of the print are clear and crisp.  But then, they
pick up stain as the rest of the print develops.   I tried using a number of
clean-water trays, but no luck.





-----Original Message-----
From: Judy Seigel [mailto:jseigel@panix.com]
Sent: Monday, March 27, 2000 3:40 PM
To: alt-photo-process-l@sask.usask.ca
Subject: sumi ink for gum




On Mon, 27 Mar 2000, Keith Gerling wrote:
>
> While we're on the subject: the other day you mentioned using Sumi ink.  I
> couldn't find the green bottle, so I got what I could, but haven't tried
it
> yet.  Two questions for you:
>
> 1.  Why the green bottle?  What kind of problems should I expect if I
can't
> find it?

I was told that the green bottle was the better quality (on this list
incidentally), and found it worked much better than the ordinary brand.. I
think I got it (couple of years ago) from Daniel Smith.

The label is in what I take for Japanese, made in Japan, has a tiny
sticker on it says

Black Sumi ink KF12, 12 ounces, Yasumoto & Co, So San Francisco, CA.


> 2.  What should I use as a start. i.e., if I use "x" amount of ivory
black,
> what amount of sumi ink?

This I'm sorry I can't begin to guess -- because I do the one by drops &
the other by eye or by weight, or both by eye... Suggest you mix the sumi
with gum arabic, counting drops of each until you get what LOOKS right &
then test...

The difference with the vin ordinaire was in covering power. The other was
simply a pale gray. The green is stronger, but I usually also mix with
some black paint -- it's not entirely trouble free, tendency to stain
(which may be why the added paint helps -- makes mix less thin, more
viscous) for instance, but worked better for me than the blacks I'd tried
til then. Next I'm going to try some DS ivory black....

good luck -- & hope you'll let us know..

Judy