Diffusion Transfer Printing ("Polaroid" peel-apart) recipes

[alecrmyers]

I have not (yet) got a DEHA/uracil developer to work with a paper negative. Having said that, I haven’t spent a lot of time trying. I will give it a go tomorrow.

off the top of my head:

Your developer should likely be 15-20% by weight of -ium hydroxide.
CMC is at your discretion
Uracil looks about right, a little high maybe but not crazy
AEEA try half that
DEHA looks low but I suppose will depend on your negative material, so if you get a well developed negative then I wouldn’t mess with it too much

Receiver part A is merely a solution of PdCl2 in water, the acid is there only just enough to dissolve the salt (as the tetrachloropalladate ion), a little excess doesn’t hurt but it’s slow to dissolve so add a few drops at a time and leave it to stir for 20 minutes in between. 100 drops of HCl (you don’t say what concentration so I’m assuming hardware store “muriatic”, which is usually 31% by weight) seems very high.

Receiver part B looks massively too rich in palladium: I would try 5 drops of part A and work from there. Look for something between the colour of pale urine and a fine brandy after adding the borohydride.

 

[Qebs]

Thanks Alec, I really appreciate this.
I will try your suggestions.

Hydrochloric acid 0.1 M
And I found I needed a lot to get the PdCl2 to dissolve.

As well, I needed a lot of part A to work.
The day before I tried again at 25 and 35 drops of Part A and image quality was low. It was faded and low contrast.
I need to look at my notes, but I think 60-70 worked, but I did the less educated thing and just used 100.
Could too much PdCl2 or part A give bad highlights.
Either blown out or creamy/muddy?

 

[alecrmyers]

Thanks Alec, I really appreciate this.
I will try your suggestions.

Hydrochloric acid 0.1 M
And I found I needed a lot to get the PdCl2 to dissolve.

In that case use 10ml of your 0.1M HCl and 10ml of distilled water, and 20mg of PdCl2. Yes, it will take a while to dissolve.

A few drops of 0.1% PdCl2 is plenty for 20ml of silica. The problem is your developer, not your paper. Increase your hydroxide as I suggested and try again.

 

[analogwisdom]

This is the best I've been able to get with the Cellulose Acetate (CA)/palladium coating, so far:

View attachment 416839

This is with Dimezone S in the developer. It appears to give a speed increase over Metol when used on CA paper, but first tests suggest a loss of density on silica.

Looks good! I wonder if the speed increase over Metol is due to degradation of Metol in the alkali solution?

https://pdf.benchchem.com/52/Preventing_Metol_degradation_in_aqueous_solutions.pdf

Interesting little paper I found. When I have used metol the developer has instantly turned deep red when I'm mixing it in, so I must be doing something incorrectly.

 

[alecrmyers]

Looks good! I wonder if the speed increase over Metol is due to degradation of Metol in the alkali solution?

https://pdf.benchchem.com/52/Preventing_Metol_degradation_in_aqueous_solutions.pdf

Interesting little paper I found. When I have used metol the developer has instantly turned deep red when I'm mixing it in, so I must be doing something incorrectly.

I don't think so. I've had developer with Metol at KOH 20% by weight sitting on the bench for 8 months and it's fresh as the day it was mixed.

A quick view of that paper indicates it's talking about oxidation of the Metol. In the developer is 6% DEHA whose primary purpose is an oxygen scavenger in high pressure boiler systems. (That's the only reason it's affordable.) I don't think there's much oxygen left in the aqueous system with that present.

My naive understnding of the way superaditive developers work is that the Metol reduces the silver halide and the second developer (DEHA) reduces the oxidized Metol (I don't know what its oxidation product is, I'm afraid) back to Metol. So I would expect the Metol to be safe until all the DEHA is oxidized first. At 6% by weight the DEHA is about 0.67M, and oxygen saturated water has an oxygen concentration of 2.4x10-4M, about 3000 times lower. I think the Metol is safe.

That's my back of the envelope analysis.

>When I have used metol the developer has instantly turned deep red when I'm mixing it in, so I must be doing something incorrectly.

Did you add it before or after the DEHA?