Amidol Concentrated Suspension

[Jay DeFehr]

Those of you using amidol print developers for silver chloride papers might be interested in a formula I'm currently using with excellent results. I'm making a solution of Ascorbic acid and benzotriazole in propylene glycol, and adding amidol after the ascorbic acid an bzt have dissolved, and when the solution is still warm, but not hot. Some of the amidol dissolves, but most remains in suspension. Since there is no air or water in the solution, the amidol is preserved, and everything dissolves readily when diluted in a 3% solution of sodium sulfite to make a working solution.

DeFehr Amidol Suspension Developer for Silver Chloride Papers:

Propylene glycol 60ml
Ascorbic acid 10g
BZT 1g
Tea 20ml
Glycol to 100ml

Shake well, and dilute 1:50 with 3% sodium sulfite solution (about 5 tsp in a liter of water) to make a working solution. The pH of the working solution should be very near 7, and will keep for several days. Develop silver chloride papers 1 minute, and bromide papers as needed. Gives neutral tones with Azo and Fomalux, and warm tones with Slavich Bromoportrait.

I don't know yet how long the concentrate will last, but I expect it to have an excellent shelf life based on my experience with similar stocks.

[Eric Woodbury]

Jay, am I missing something? Where's the Amidol?

[Jay DeFehr]

I'm an idiot. Thank you Eric. The formula should read:

propylene glycol 60ml
ascorbic acid 10g
BZT 1g
TEA 20ml
AMIDOL 10g
glycol to 100ml

I hope this makes more sense!

[Herb Cunningham]

I have wanted to try propolyene glycol instead of my usual water based pyrocat hd.

I found a number of sources, one, www.vallleyvet.com has it for $18.95 a gallon. Is that the correct stuff? Hard to see what kind of purity levels etc, although they feed it to cows, so should be ok??

Some other sources have it for $50+ a gallon.

[Jay DeFehr]

Herb,

It should be fine. I get mine from Thechemistrystore.com (http://www.chemistrystore.com/Propylene_Glycol-Propylene_Glycol_1_Gallons.html), but I should try to find a local source to avert shipping costs. There's a vet just across the street; I think I'll try them.

[j.e.simmons]

Very interesting. I would think one could add KBr and adjust it and the BZT to change the print color as desired, depending on paper.
juan

[Eric Woodbury]

The vet supply PG works fine. That's what I use.

Jay, So you're venturing into Amidol. I'm wondering -- you have PG and Glycol. Isn't that two inert solvents in one developer? I know you need one to dissolve the amidol because amidol just won't go into TEA. What is the glycol doing for you?

[Jay DeFehr]

Eric,

I've only been paying around with amidol for print developers. I use PG (Propylene Glycol) as the solvent to keep air and water out of the concentrate. The TEA compensates for the ascorbic acid by converting it to some other form, in order to keep the pH up, while retaining the stain control and preservation properties of the ascorbate. When the concentrate is diluted with the 3% sodium sulfite solution to make a working developer, the pH is buffered at 7. The amidol doesn't all dissolve in the concentrate; in fact, most of it doesn't dissolve; that's why I call it a suspension. The amidol is suspended in the ascorbic acid solution, and dissolves when diluted with the sulfite solution to make a working developer. A solution is preferred, but not strictly necessary, especially for a print developer, and the advantages far outweigh the disadvantages in this case.

Juan,

You're absolutely correct; BZT/KBr can be added as desired to fine tune print color with various papers.

[John Bowen]

Jay,

so If my math is correct, you only use 2g of Amidol in 1 liter of working solution. I use the MAS Amidol formula that takes 8g of Amidol/liter. At about $0.50/gram that sure would help keep costs down.

I'll have to get some TEA and mix up a batch. Thanks for sharing and please keep us posted on what you find re: keeping properties.

[Jay DeFehr]

John,

Yes, your math is correct; 2g amidol, 2g ascorbic acid, .2g bzt, 30g sodium sulfite/ liter. I'm on my third printing session in as many days with the same working solution. I'm making tiny prints (6x9 cm up to 4x5") in 250 ml of working solution. I keep expecting the solution to wear out, but amidol is pretty amazing stuff!

I've read mixed reviews of the Fomalux 111 paper, but I'm getting really nice prints from it.

[sun of sand]

you can dilute amidol down and many have done so but more for bromide papers, i believe
whats the difference between this and mas amidol with contact paper? any, i dunno

amidol is very easy to mix up so i dont understand why youd need this
it seems like MORE work in the end

just wondering why

[Jay DeFehr]

I'll try to address your points in order.

This formula is not a diluted version of MAS Amidol, it's completely different.

I don't see any difference in results between MAS amidol and my formula, to be honest. Both formulas work about the same in the tray, and produce similar print colors.

Advantages to my formula:

It uses about 1/4 as much amidol for the same results

Lasts longer in the tray

To make a stock solution one need only add a few teaspoons of sulfite to water, add some concentrate, and stir; quick, easy, simple, and does not require a scale to weigh out dry chemicals. This makes it far simpler to make any desired quantity of working solution, and limits exposure to amidol powder.

If it were easier to do so, I could as easily make this formula from scratch each time, instead of making a concentrate, but for me, this is MUCH simpler. A liter of concentrate makes 50 liters of working developer, so the brief time necessary to make up the concentrate is insignificant compared to the time and effort saved over 50 liters of working developer. I don't use amidol print developer exclusively, but perhaps that will change, since my formula is relatively economical, and easily adjusted for use with different papers.

I'm not interested in converting anyone away from MAS amidol, or any other developer they're happy with. I'm simply sharing my formula with anyone who is less than satisfied with their current amidol developer.

[John Bowen]

Jay,

When you say the amidol is in suspension, is it truly in suspension or does it settle to the bottom? The reason I ask is I was wondering if the Amidol suspension bottle needs a good shake prior to dilution.

Thanks,

[Jay DeFehr]

John,

The solution is very dark, so it's hard to be sure exactly where everything is, but I always shake it up before measuring it out.

[Daniel Stone]

this could prove to be very nice for those of us looking at amidol as a way of developing.

after working for M+P this summer, and examining their portfolios in person, I'm hooked on the process(all of it!). Moreover, having a more economical way of printing with amidol-based developers sure is even more of an incentive :).

-Dan

[Jay DeFehr]

My working solution seems to lose potency sometime during the third printing session, according to my evaluation of prints. As a result, I make up a fresh working solution after the second printing session, and this seems to be completely safe. Results might be different with larger batches and fewer prints; I purposely overworked my working solution to find a point of failure. Better safe than sorry.

[Hugo Zhang]

Hi Jay,

I have just come across this thread as I am trying to find the best way to print my 14x17 and 16x20 negs.

I love Azo/Amidol combination as I find my Azo contact prints are better than contact prints done with Ilford paper. But my problem is I don't have a home darkroom and have to use Mt. SAC, a local community college, darkroom which has a 2 1/2 hour sesson time. The use of a 45 enlarger with Azo or Lodima paper means I don't have much time as each print will take at least a few minutes to expose.

I have read the Fomalux 111 paper is a few times faster than Azo and I have some paper on its way to me. I have two questions for you:

1. Have you compared prints done in Fomalux 111 with regular developer and Amidol? Are there noticable difference? Can you describe them?

2. If yes, then I am very interested in your formula. Is it possible for you to sell me some concentraded solution so I can just mix it with water at 1:50?

Thanks.
Hugo

[Jay DeFehr]

Hi Hugo,

Yes, there are noticeable differences between prints on 111 developed in amidol, and those developed in my normal developer, a soft working, metol-only portrait developer; the amidol prints have more contrast, deeper blacks, and a more neutral tone.

I haven't tested my amidol developer enough to sell it to anyone. I'm not sure how long it will last. One user said his went bad after a few months. I haven't used mine in a few months, so I don't know if it's still good. I could send you a sample, enough to make a few prints with, then you'll know if it's worth pursuing. I won't be home until April 6, and then I'm moving to Seattle, so I'm not sure I'll find time to get into the darkroom, but if I do, I'll be happy to make you up a bottle.

[cdholden]

Jay,
Have you done any more testing of this, or know if anyone else has? I'll be trying my hand at printing on Lodima soon. Extending the keeping properties of Amidol would be a bonus, as well as mixing from solution instead of powder each session. I am interested in any new comments from experience with this formula.

Thanks,
Chris

[Jay DeFehr]

Hi Chris,

Since I left my home/dark room in April I haven't done any silver printing, and I don't have access to my chemicals, etc. I don't know of anyone using this formula. I wish I could be of more help.