Re: cyanotype on glass
About gesso and cyanotype: Gesso contains calcium carbonate which is
alkaline, hence the speed loss and fading of the cyanotype image...
Probably not knowingly, you have put your Cyanotype image(s) on the
most hostile environment! ;)
Joe's suggestion seems plausible, I will add something to it: try to
mix small amt. of double strenght cyanotype stock solutions, combine
them and dilute 1+1 with hot 10% non-hardened gelatin (you may need to
up the temperature of the combined double strenght coating solution)
and coat the plate (prepared according to Joe's suggestion) just like
Joe describes. (See texts about dry-plate for a coating method... Also
see text about Galina Manikova's method of working with glass. Both
can be found on the new edition of The Book of Alternative Processes.
Also, list archive has something about Galina...)
Also see something about Beer Coating. (Henk's article -> google and
you'll find it...)
Let us know it you manage to work out a good workflow!
Regards,
Loris.
On 18.Tem.2009, at 18:10, Joseph Smigiel wrote:
Dirk-Jan,
I would try flowing an albumen layer onto the glass as was done
sometimes for wetplate collodion. Roughening the edge of the plate
first with a whetstone or sandpaper/carborundum sheet would also
probably help. I would start with the white of one egg added to
500ml distilled water, froth the solution and refrigerate, then next
day repeat and, once the froth has settled, filter the solution
through a paper coffee filter. Then you could cover the plate with
this albumen solution by holding it horizontally, pouring a pancake-
sized puddle on the plate surface and tilting the plate to evenly
cover, and then draining the excess. This works to hold collodion
to glass so I suspect it may be an adequate substrate for a later
layer of gelatin that would hold the cyanotype chemicals. Or,
perhaps one or both of the iron salts could be added to the albumen
solution before pouring.
Alternately, contact the Bostick and Sullivan company about a silane
coating solution that may work.
Disclaimer: I have never done either method with any other process
other than using an albumen subbing with wetplate. I'm just
offering suggestions that I think might work.
Joe
On Jul 18, 2009, at 6:17 AM, Dirk-Jan Treffers wrote:
dear list,
I'm trying to see if it's possible to make a cyanotype on just a
plain glass frame, in stead of on paper. I thought I had seen some
posting on this subject some time ago, but my search results turned
out with nothing... (or i used the wrong search terms, then my
mistake.,.)
Of course, the chemicals aren't absorbed by the glass, so I'd
already considerd to be needing some underlying coating.
I've tried two up to now, but with very unsatisfatory results:
1. I've coated the glass with a hardened gelatine solution (20%
gelatine (20 gram gelatine + 80 gram water), some added drops of
100% thymol in alchohol and 5 ml 40% glyoxal).
2. I've roughened the glass with some carborundum, cleaned it with
common household ammonia, coated it with a mixture of acrylic gesso
with very fine marble powder and coated the glass with that.
The first method resulted in a very slippery gelatine layer, that
seemed to wash away a bit whe developping in water. (or maybe I
just need more glyoxal), but even without that, the picture just
didn't have the charm of the one I made on paper.
The second method resulted in a very faint image (if it would still
work the same way as on paper, I would have to increase my lighting
time from 6 minutes to approximately 48 to 96 minutes, can't
imagine that that would 'solve' my problem). Apart from the very
obvious brush strokes in the gesso (does anyone have a solution for
that as well? Since it was just a trial-and-error run for me, I
didn't bother very much about the brush strokes, but it seemed
really difficult to get an even coating...), the contrast of the
image was very poor, and even started to fade after afew days.
Am I trying to do the impossible here, or are there any imporant
steps I'm just missing? I'm just a newby to all this... Have done
some cyanotype and gumprints, but with only the top of my
washingmachine in my bathroom, I'm not nearly as much as a pro as
you guys... Still, I like the proces and the results very much, and
the results on paper, I'm (quite) satisfied with. So, should I just
stick to paper, of try the glass-thing, with some help from you
guys??
thanks a lot already!
kind regards,
Dirk-Jan (unpronounceble for non-dutchies, I know, for a decade or
two I've been listening to the name deejay as well, so if you call
me that, I won't be offended)....
|