Benzotriazole Questions

[Kevin Crisp]

I haven't used this for anti-fogging before. I have some (actually quite a bit) of New Seagull VC I bought at Freestyle in 2001. It has been stored for 22 years at 37F. Printed on some of it yesterday. It looks great, until you compare an unexposed edge to new paper. Then it looks a little grey. The difference is subtle enough it is far from obvious if you don't do the side by side comparison. It is slight, but does affect highlights a little.

1. Will using Benzetriazole help with this?

2. Picker's version (going from memory here) was 2%. How many grams would it take to mix up 16 oz of 2% solution? Around 10g?

3. Is there any disadvantage to mixing up 2% vs 1%?

4. Dissolve it in hot distilled water?

Thanks.

[xkaes]

I'd do a simple test first. Compare an unexposed & fully developed and fully fixed piece of paper to an unexposed & undeveloped and fully fixed piece of paper. Still see a difference?

Start doing tests with the least amount of ANTI-FOG you can. If 1% solves the problem, stop there. If not, double the ANTI-FOG. Rinse and repeat as needed.

A 1% solution is 1 gram in 100 milliliters or 0.1 gr in 10 ml. A 10% solution is 10 grams in 100 milliliters or 1 gr in 10 ml.

Use whatever temperature water you need.

How much to add to your developer? Use whatever Picker suggests -- but if it works on the first try, cut the amount in half and try again. Rinse and repeat as needed. You want to use as little as possible.

[Drew Wiley]

2% would be 20 grams per liter, or 10 g per 500ml. Benz dissolves in room temp water, but somewhat warmer water might help. Yes, if you're going to keep it around, use distilled water. But you can simply add it directly to your paper developer instead : Try 0.2 g (2/10th) benz powder per liter of developer, provided your developer itself is going to be diluted down to 1:2 or 1:3 for use. And expect some color shift toward cooler with your paper, along with slightly slower dev time (benz is a restrainer). Your highlights and margins should come out a little cleaner.

[Tin Can]

Just got a new bottle

I still play with old paper

Now I want to try old plates

[RichardRitter]

Fred said one ounce working strength (1%) to one quart of working developer.

You can use up to 8 ounces to 1 quart of developer. You will want to lengthen the time in the developer. and you may notice a change in contrast.

Best to start with a 1 to 1 and test.

If mixing from power hot water around 110 degrees F. and stir.

[nolindan]

I dissolve it in alcohol to 10% w/v - it's not very soluble in water. 1/2 tsp in 32 oz (.25g/l) seems to work (going by memory here, take with lots of salt).

If the fogging is slight then you can try a dash - say 1/2 oz - of P. Bromide (10% in water). P. Bromide is a good addition to developer if you are having trouble getting clear highlights in the natural course of things. Another 10% solution that is nice to have on hand is S. Carbonate - a few ounces can deepen blacks.

[Doremus Scudder]

I've found a 1% BTA solution in water to be more workable than a 2% one, simply because it stays in solution better and doesn't crust up around the bottle mouth.

I'd suggest starting with 2.5 ml of a 1% BTA solution per liter of print developer and add more in 2.5ml increments until you get the restraining effect you need or until you reach about 30ml/liter or so.

If BTA won't completely recover age-fogged paper, a few seconds in a reducer will get the paper back to white before anything happens to the highlights. I usually use a potassium ferrocyanide/potassium bromide bleach. Alternately, you can just locally bleach the highlights of the print to get them to the right amount of sparkle, especially if the paper fogging is minimal and you trim the borders of your prints before mounting.

Best,

Doremus

[Michael R]

It is much more soluble in either alcohol or an alkaline solution. A sodium carbonate solution is perfect.

[Doremus Scudder]

Michael,

How do you mix BTA in a carbonate solution? How much carbonate and BTA? That might be a better solution (pun intended) than the 1%.

Doremus

[Kevin Crisp]

What is "BTA"?