Anti-fog

[StanW]

I've acquired a variety of old papers, and I need some advice on using benzotriazole with them.

[Les McLean]

First off mix a 1% solution of benzotriazole, 1 gram to 1 litre, and use very hot water as this chemical is not easy to dissolve.

I'd suggest you process a sheet of unexposed paper to determine the degree of fog present. Having done that start by adding 15ml of the 1% solution to your developer and process a second sheet or part of a sheet and compare it with the first test. If there is still fogging evident add 5ml the 1% solution to your developer and try again. Continue this until the fogging is either aceptably reduced or totally eliminated. I say this because there comes a point when adding benzotriazole will no longer do anything other than change the characteristics of the paper.

For example, I have added up to 120 ml of a 1% solution of benzotriazole to the working developer to increase the contrast of the paper by chemicaly inhibiting the development of the highlights thereby increasing the contrast. I have also used this method to cool the final print colour especially when using a warm paper.