View Full Version : Question about pre-made Emulsions

08-23-2008, 01:12 PM
It seems Rockland, Roelli, and Kentmere all market Variable contrast photo emulsions that you can use at home to coat objects.

My question is this: It was my understanding that the way a variable-contrast photo paper is made, is to coat it with 2 emulsions..one high contrast and one low contrast, both having sensitivity to different colors of light, so the color filters one uses can influence the final contrast.

How do they get variable contrast characteristics into ONE emulsion in these products?

Ian Grant
08-23-2008, 01:54 PM
No variable contrast emulsions are coated as one emulsion and always have been. So there's no difference.

Ron (PE) has given details of how Multi Contrast emulsions are made in the Emulsion making section


08-25-2008, 09:27 PM
I think Ron mentions a couple of exceptions (earlier papers mostly, IIRC), but as Ian said the two emulsions are generally mixed together and coated as one layer.