Re: Carbon on glass
Hi, Marek,
I have used Sumi ink for transparent black with good results.
Your idea of coating glass to get a tissueless carbon, so to speak, is
interesting, but I don't see very well the benefits over the usual way
of transporting exposed carbon tissue on a glass sheet. Do you get good
definition exposing from the back?
Tom Sobota
Marek Matusz wrote:
Thanks for the tip and the link. Sounds like very similar phenomenon as
described in the dissertation. I will try my trusty Daniel SMith brand,
but I guess powdered pigments are safest.
Marek
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Date: Sat, 8 Sep 2007 11:36:38 +0200
From: halvor@ydl.net
Subject: Re: Carbon on glass
To: alt-photo-process-l@usask.ca
Hi, yes .. Some watercolours contains ox gall wich can harden
gelatine. Winsor & Newton is supposedly one case. I have only tried
Holbeins which works fine.
(problem is mentioned on page 65 in a thesis here
_http://www.katayoundowlatshahi.com/research.php_ , there is a lot
about carbon on glass in that thesis & very interesting images,
recomended :-)
Halvor
On 9/7/07 5:48 PM, "Marek Matusz" <marekmatusz@hotmail.com> wrote:
All,
I need some help from carbon printers here. I have been
experimenting with carbon on glass. My pigment was lamp black. I
used back exposure of the glass plates in the sun and it all
worked very nicely. It really seems so easy. I then decided i
wanted a transparent black and made gelatine mix with perylene
maroon and phtalo green ( this has been my favorite black for
gum printing). It really gave a nice black gelatine solution. I
coated a few glass plates, sensitized, exposed, but they were
all insoluble, no image was formed. Something was not right, so
I remelted the gelatine and covered some more pieces of glass,
cut the dichromate and exposure, but with the same end result.
The gelatine was insoluble and no image. AT this point I was at
a total loss, so I tried a different batch of dichromate, but
with same result. Finally I placed a dried, but unsensitized
glass plate in hot water. To my surprize the dried gelatine mix
would not redissolve in hot, hotter and very hot water. SOmehow
one of the pigments or something else in the watercolour paint
that I used as a pigment source made the gelatine totally
insoluble once dried. I had an extra glop in the fridge and
remelted it again and it melted fine.
Has anybody seen that before? Are there some pigments that are
not compatible for making carbon tissue? What do people used for
transparent black?
As a side comment I find that carbon on glass with back exposure
(did I mention earlier that it is all back exposure) is
relatively easy, much easier then gum. Gum does not stick to
glass, so the glass needs to be treated, gelatine sticks to
clean glass very nicely. It is also easier to coat with
gelatine as it sets quickly and the plates can be moved from the
flat surface.
Marek
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