cyanotype with normal negatives (newb question)

[Vlad Soare]

I could not get a decent cyanotype with normal contrast negatives. Neither with the new process (bought pre-mixed from Freestyle), nor with the old one (mixed by myself). They were simply too low in contrast.
However, I got good cyanotypes from negatives that I had made for the vandyke process (which are extremely overdeveloped, so contrasty that they're almost impossible to print on silver halide paper).

[Vlad Soare]

I have found that Kodak TMax has a UV filter in the base of the film so making decent alt process prints using TMax is impractical. I shoot TMax for silver prints but shoot Efke for alt process prints. It is a PITA but the results are worth the effort.

Only T-Max 100 has built-in UV filters. T-Max 400 hasn't. It's very different from TMX and has nothing in common with it, except the name. I have used it to make vandyke prints, and I got exposures of around five minutes. So there was no apparent UV blocking.
I find T-Max 400 to be perfect for alternative processes because of its straight curve. It has no shoulder. No matter how hard you overdevelop it, it still retains contrast and details in the highlights.

[D. Bryant]

I could not get a decent cyanotype with normal contrast negatives. Neither with the new process (bought pre-mixed from Freestyle), nor with the old one (mixed by myself). They were simply too low in contrast.
However, I got good cyanotypes from negatives that I had made for the vandyke process (which are extremely overdeveloped, so contrasty that they're almost impossible to print on silver halide paper).

I agree with Vlad about needing negatives with a density range of about 2.5 log and about TMY-2. Cyanotypes made with low contrast negatives tend to be muddy.

Double coating shouldn't be necessary in my experience when you use a good non-hostile paper for printing.

Don Bryant

[D. Bryant]

Thanks all...that's helpful. The book chapter in particular. I guess I'll have to give it a try.

Sorry, one more question: in the book it says "Potassium ferricyanide is a stable compound that only becomes a risk if it is heated beyond 300°F or if it is combined
with an acid." Aren't there acids in the darkroom sometimes? I'm not a chemist. I'm just wondering how safe it is to use. I do my darkroom stuff in a shared bathroom with patient roomates, but I don't want to kill anyone.

Thanks!
Paul

Cyanotype is seriously safe in the average darkroom. The process has been used for well over a century and I'd wager no one has ever died from potassium ferricyanide when used in the typical darkroom.

Mike Ware's New Cyanotype is notably more poisonous - per Dr. Ware himself so beware.

Don Bryant

[Tom Monego]

A friend, while we were in college got cyanide poisoning from doing full nude body prints on a cyanotype emulsion. It was a low level poisoning, but she was in the hospital for a couple of days. She probably did 20-25 prints before the symptoms were too much to ignore. I ran into her 25 years later, so no apparent after effects.
I liked gum printing myself, but you can't get potassium or ammonium dichromate any longer.

Tom

[sully75]

Tom, luckily I think the market for full nude body prints of me is really limited.

I thought that potassium dichromate was pretty freely available? In my younger days restoring musical instruments, I used to use it without gloved. Doh!

[Vlad Soare]

Photographer's Formulary list potassium and ammonium dichromate on their website. They don't ship it outside USA, but they do sell it nevertheless.

[D. Bryant]

A friend, while we were in college got cyanide poisoning from doing full nude body prints on a cyanotype emulsion. It was a low level poisoning, but she was in the hospital for a couple of days. She probably did 20-25 prints before the symptoms were too much to ignore. I ran into her 25 years later, so no apparent after effects.
I liked gum printing myself, but you can't get potassium or ammonium dichromate any longer.

Tom

Tom,

1) You don't get cyanide poisoning and live to tell about it. She may have had some other ailment from chemical sensitivity. No one I know has ever recommended exposing your nude body to cyanotype solution. And if there was dichromate in the solution she may have had a reaction from that. Anyway normal use of Cyanotype solution is just as safe as using most any other darkroom chemical when handled properly.

2) AD and PD are still available as photo chems from several different sources at least in the US.

Don Bryant

[stompyq]

Mike Ware's New Cyanotype is notably more poisonous - per Dr. Ware himself so beware.

Don Bryant

Is this b/c of the dichromate? I remember using that stuff for toning long ago and didn't give it remotely as much respect as i gave ferricyanide (which scared me to death). I'am planning to go in to cyanotypes using digital negs at home and can't decide which process to go for (old/mike ware)

[Vlad Soare]

Is this b/c of the dichromate?

No, it's because of the ferric ammonium oxalate.
The old cyanotype process uses ferric ammonium citrate instead, which is harmless.
Oxalates are toxic.
Potassium dichromate is optional in the new formula, and not used at all in the old one.

I remember using that stuff for toning long ago and didn't give it remotely as much respect as i gave ferricyanide (which scared me to death).

Scary name, isn't it?
Actually, it should be the other way around. Dichromates are very toxic, while potassium ferricyanide is harmless unless you do something really stupid (like, say, mixing it with sulfuric acid).

I'am planning to go in to cyanotypes using digital negs at home and can't decide which process to go for (old/mike ware)

Personally, I'd go for the old one. It's simpler, cheaper, and seems to me to be more consistent.
I found the new cyanotype solution to be very inconsistent. I never knew what to expect from it. Admittedly, I had bought it pre-mixed, so who knows, maybe there was something wrong with my particular solution, and not with the formula itself. I didn't try to mix it myself.