I do with mine - I'd be interested to hear if others do as well. It seems like you could use a little less since there is less absorption by the paper but I usually use the same volume.
Originally Posted by ira_
It has been a while since I've done any cyanotypes, but I used to do a lot of it. I don't think a lot has changed in those few years, the process now being something like 160 years old.
I suspect that your paper has no sizing. You CAN use unsized paper; I did that all the time, but I used Arches 88, which is a very expensive and beautiful paper made for intaglio printing; the cyanotype soaks in just like blotter paper, and that introduces lots of interesting problems but makes it possible to get great "black". By computer paper, don't you mean ordinary white paper like "copy paper"? Sizing using starch or arrowroot might help a lot, but as someone above suggested, why not just get some watercolor paper? It comes presized, and is much better paper with much heavier weight; it will hold up much better in the wash and since the cyanotype doesn't soak deeply into the fibers it doesn't require the longer wash times.
The suggestions above regarding color changes indicating exposure are right on.
In sunlight here in western Washington (maritime climate) an exposure of 1/2 hour would be about the minimum even on our unfortunately somewhat rare clear days. Despite the obvious climatic differences, it would probably not be a lot different where you are, since the sun is still 93 million miles away, but you may be getting a higher proportion of UV which would shorten it a bit; I don't know, but maybe somebody does. A rather heavy, fairly contrasty negative without a lot of base+fog would be ideal.
Do consider making photograms, just laying stuff on the paper using no negative at all. It's a really great medium for that. Three dimensional objects produce varying degrees of value and sharpness/blur, and transparent objects introduce very interesting images because they become lenses of a sort, concentrating light in some places and dispersing it in others.
I have had the best results using Beinfang 360 paper. It is a thin paper, almost a tracing paper, and advertised for use with magic markers because it has no bleed-through. It is very easy to get a nice even emulsion coat on the paper and it has very good wet-strength. I tried Cotman watercolor paper with really bad results: blotches where the emulsion soaked through to the other side; emulsion turning blue from additives in the paper; wavy rippled paper ...
And Beinfang 360 paper is _cheap_ (comparatively speaking). http://www.dickblick.com/zz106/04/
http://www.alternativephotography.com/ is a good site for cyanotype information.
How do you keep the Bienfang 360 flat after coating? It is a great paper for cyanotypes, but large sheets wrinkle considerably after the emulsion starts to dry.
And Randy, though I've never actually measured the amount of the two coatings, my impression is that the second coat requires more than the first since the nap of the paper and sizing has been disturbed by the first coat. The second coat seems to soak in quicker and to a greater degree IME.
Your biggest issue by far and away is your exposure method. Cyanotype is mostly only sensitive in the UV region, and is about 10,000% less sensitive than silver gelatin even when it recieves the spectrum it is sensitive to. You need to use a UV light source. Black light bulbs will work, but will still require long exposure times. My 1000w Nuarc can take between 20-30 minutes or even more to expose an 8x10 print. Because of the self masking nature of cyanotype, overexposure isn't easy to do, so error on the side of too much at first. Depending on the wattage/type/proximity of your black lights you might try 2 hours for starters.
Also, since you are going through the time and effort, I'd recommend getting some nice paper.
Regular bulbs are worthless.
Hope this all is of some help
Last edited by JBrunner; 09-27-2008 at 08:24 PM. Click to view previous post history.
That's just, like, my opinion, man...
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I hang the paper from a line by the corners to dry, like a bed sheet, and it dries relatively smoothly. I tape the sheet to a plastic board to coat it and there is a 1/8" margin of uncoated paper. The biggest I have done is 11x14, though.
Originally Posted by smieglitz
The finished cyanotype has a definite crepe-paper 'wrinkle' to it that I rather like. I haven't tried dry-mounting B360. I have thought of paper-mache'ing it to the mount board with methyl cellulose.