A blended ferrocyanide print process

koraks said:

Welcome to Photrio; beautiful prints @Ksnbdooanndin !

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+1

Ksnbdooanndin said:

hi every one. this summer I read the article from @koraks and immediately tried it. my results were pretty similar to his tones, thinking "uh ok" and moved on. but two days ago I found this tread and raghu's tones are from another planet. so I tried again, and again and again. The crunchy black wasn't there. Today, on the last try I got something closer to him.
paper used was Fabriano unica, same sensitiser traditional solution A and 20% solution b plus ammonium chloride.
no PFC in the developer for the first one and some in the second one. What's interesting, while playing around I added some ammonium chloride in developer to compensate the excess of ofc and it worked!

@Raghu Kuvempunagar does it sound right?
why should I need more than normal?

I feel both a bit underexposed since there is a lot of copper and only a few of iron.
I'll might play a bit more aiming the blackest tone and then linearize it.

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Ammonium Chloride serves the following purposes in FerroBlend process:

1. As a sensitiser additive, it increases the warmth of the print. As warmth is due to the formation of more Copper Ferrocyanide pigments, this also has the effect of pushing blue towards black. It has the similar effect when used as developer additive. Used this way, it functions as a creative control in printmaking. Effect obviously varies with concentration and paper.

2. When using buffered paper that doesn't take acidification well (e.g. Bristol papers), coating the paper with Ammonium Chloride before sensitising, reduces the detrimental effect of the buffer (e.g. reduces overall stain by reducing rogue pigment formation).

3. It prevents bleeding in deep shadows when using smooth papers probably due to the formation of more Copper Ferrocyanide pigments than without.

Ammonium Chlroide can be used in FerroBlend process in the following ways:
1. As a pre-coat to the paper before sensitisation.
2. As a sensitiser additive.
3. As a developer additive.

Yes, if you add Ammonium Chloride to the sensitiser/developer, it increases the warmth of the print. Adding controlled amounts of Potassium Ferricyanide to the developer further aids this.

You can also push blue towards black by toning with the toner discussed here.

Ksnbdooanndin said:

Raghu, what you did is amazing!

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I'm happy that you find the process interesting. Wish you continued success with the process. And do post your prints in this forum.

thank you both @koraks and @Raghu Kuvempunagar.

Raghu, I have some questions for you.
for me its easier to find bicarbonate of ammonium since they use it in the pastry industries. Will it work for the toning purpose?

what percentage of ammonium chloride do you suggest for a precoat?

Will try some prints today

1-2 ml of 20% Ammonium Chloride solution would be good for a precoat. That's about 0.2g - 0.4 g per A4 sized sheet.

I've not tried Ammonium Bicarbonate but I think it should also work Add till bubbling stops and a deep blue solution forms. Initially there will be a precipitate which subsequently goes back in to the solution. You can use liquid Ammonia in place of Ammoniym Carbonate but the smell of Ammonia can be very unpleasant.