Ilford IIN-3 Chromium Intensifier

[Ian Grant]

For controlled intensification of negatives. This intensifier is not liable to produce stains.

BICHROMATE STOCK SOLUTION
Potassium bichromate 100 g.
Water to make 1000 c.c.
This solution keeps indefinitely.

BLEACHING SOLUTION A
Bichromate stock solution (as above) 100 c.c.
Hydrochloric acid (conc) 2·5 c.c.
Water to make l000 c.c.

BLEAcH1NG SOLUTION B
Bichromate stock solution (as above) 100 c.c.
Hydrochloric acid (conc) 12·5 c.c.
Water to make 1000 c.c.

Bleaching Solution A gives more intensification than Solution B.
Whichever solution is selected should be freshly mixed. Immerse the washed negative in the bleaching solution selected until it is completely bleached, then wash until the yellow stain is removed and re-develop, by white light, or after exposure to light, in an M.Q. or P.Q. developer. Wash the negative thoroughly before drying.

Ilford's IT-8 toner is similar using a Bichromate bleach then a Pyrocatechin re-developer. I'd suggest using Pyrocat HD as the re-developer as you get staining from the chromium and the Pyrocatechin re-enforcing the silver image.

[An Le-qun]

There's no H2SO4 used in this intensifier.

Oops! I just made a substitution of my own! No wonder I have such problems in the lab.
Let's try this again.... Any suitable substitutes for HCl?

[haryanto]

i've try it, it seem dont like selenium which intensifier negative and raise contrast,
Ilford IIN-3 Chromium Intensifier very good for underdeveloped negative and intensifier it in all range density so contrast just litlle rise, hardening is a must otherwise it's easily scracth
thanks Ian, very usefull