kevs
Member
Hi all,
I'm beginning to experiment with the Kallitype process, and am using Ferric Ammonium Oxalate (green) as it's much cheaper and much more avaliable than Ferric Oxalate. I am aware of Dr. Mike Ware's comments on this substance, (see his comments quoted at Dead Link Removed. My first plan is to coat the paper with the iron salt, dry, then add the silver nitrate.
Anyway, that's the background. My observation, made whilst experimenting with FAO-based Cyanotypes, is that after coating the FAO onto paper, it emits ammonia and turns yellow (from green). I haven't read about this observation elsewhere.
There are two explainations that i can think of:
1) The FAO is reacting with the paper's size or buffer;
2) The FAO is reacting to atmospheric gasses.
Whilst i think that 1) is possible, my money is on 2). The reason i say this is because i coated FAO onto a strip of newspaper and even that emitted
ammonia.
Does anyone know what reaction is happening here? What is the product left on the paper - i'm guessing Ferric Oxalate as it's still light-sensitive; I have made successful Cyanotypes with it.
Thanks for any information. I'll let you know how my experiments go.
kevs
I'm beginning to experiment with the Kallitype process, and am using Ferric Ammonium Oxalate (green) as it's much cheaper and much more avaliable than Ferric Oxalate. I am aware of Dr. Mike Ware's comments on this substance, (see his comments quoted at Dead Link Removed. My first plan is to coat the paper with the iron salt, dry, then add the silver nitrate.
Anyway, that's the background. My observation, made whilst experimenting with FAO-based Cyanotypes, is that after coating the FAO onto paper, it emits ammonia and turns yellow (from green). I haven't read about this observation elsewhere.
There are two explainations that i can think of:
1) The FAO is reacting with the paper's size or buffer;
2) The FAO is reacting to atmospheric gasses.
Whilst i think that 1) is possible, my money is on 2). The reason i say this is because i coated FAO onto a strip of newspaper and even that emitted
ammonia.
Does anyone know what reaction is happening here? What is the product left on the paper - i'm guessing Ferric Oxalate as it's still light-sensitive; I have made successful Cyanotypes with it.
Thanks for any information. I'll let you know how my experiments go.
kevs
Last edited by a moderator: