Cyanotype on Glass??? (new formula)

[evanjjedwards]

Does anyone have any experience on working with cyanotypes on glass? I've found some resources for a gelatin-based emulsion to coat the glass, but these use the traditional two-part chemistry. Has anyone here ever worked with this new cyanotype process on glass surfaces?

 

[koraks]

Haven't tried it, but I don't see why it wouldn't work. Maybe just give it a try?
And welcome to Photrio!

 

[NedL]

Interesting idea! I'm just guessing, but you might want to use a gelatin with a low isoelectric point... ( e.g. not pigskin gelatin ). Let us know what happens if you try it!

 

[koraks]

you might want to use a gelatin with a low isoelectric point

I wonder if it matters much. In case of yellow/brown fog, add a pinch of citric acid and call it good. But that's guessing on my part, I admit.

 

[NedL]

having not done it, I'm not sure... I wouldn't be surprised if type of gelatin affects clearing and also adhesion to the glass at new cyanotype pH.... and I wouldn't be surprised if some types of gelatin just work better in other ways ( contrast, max "blue", etc...

 

[koraks]

Having adhered gelatin to lots of things, I know that adhesion is mostly a matter of procedures, layer thickness and pre-treatment of the substrate. Gelatin is not as pH sensitive as you might think; it's pretty robust over a fairly wide range. As to contrast and dmax, I think purity is a more relevant criterion. The main issue here is that most gelatins are pretty yellow and that will make a cyanotype look slightly greenish. The gelatin I use the most when I need neutral color is in fact a porcine gelatin. Moreover, inclusions like bone matter would have an influence, but even food-grade gelatins are fairly pure these days. Now, New Cyanotype is a little fussy, more so than the classic formula, so I'm sure there will be differences between gelatins. I'd personally start with something you can easily pick up at the local supermarket and then solve any problems as they emerge.

 

[Molli]

If you do a search for Joseph McAllister Cyanotype on Glass, you'll get a bunch of links to his YouTube video, images and instructions (including a link back to here on Photrio, but that's full of dead links now).
If you have any trouble finding his pdf, just yell. I saved a heap of information back when I first came across him and some of them might not be online anymore. They're not on my phone, or I'd post the pdf at the very least, but I can find it for you easily enough when I next access my laptop.

From memory, he uses the "new" formula with Oxalic Acid - as someone who only uses the old, basic formula, I'm in the opposite boat to you in not doing it BECAUSE it uses the newer formula.

(Edited to add: Welcome to Photrio from stinking hot Australia! )