A blended ferrocyanide print process

[jmoche]

Sounds great! Let us know how it goes with the students.

What inkjet paper have you been using?

The stain issue is generally due to the buffer in the paper which needs to be neutralised before coating. Impure Copper Sulphate and high humidity could also be other causes as noted by Andrew.

I will probably be a few more weeks before I get the students involved, so I still have some time to get my own process worked out a little better. So far as I know, there are no buffers in the inkjet paper. I have a huge supply of cheap watercolor papers, and I know that they are buffered. I soaked some tonight in citric acid and the bubbled, so they probably have a pretty high alkaline load. I tried this paper last week and the emulsion had turned blue even before exposure; I'll see if the acidification helps. As for inkjet paper, I've used three. First, Kodak Professional glossy. I bought a ton of it because I had a profile for my printer. That printer died, Kodak stopped supporting the paper, and I'm too lazy to create my own profiles, so I've been using it for cyanotypes. Second, some Red River Metallic gloss. It's not great for every subject, but some landscapes look fantastic on this paper. Finally, there are a lot of half-printed photos at the lab in school, and I take those failed photos and cut off the unused paper. That stuff is Arista Pearl.

 

[Raghu Kuvempunagar]

I have a huge supply of cheap watercolor papers, and I know that they are buffered. I soaked some tonight in citric acid and the bubbled, so they probably have a pretty high alkaline load. I tried this paper last week and the emulsion had turned blue even before exposure; I'll see if the acidification helps.

It should, even for the Cyanotype process.