Fotospeed Argyrotype Sensitizer, is used in the alternative photographic process of Argyrotype or VanDyke/Brown printing.
The Argyrotpe print utilizes an improved iron-silver base compound for its sensitizers. This improves image permanence and allows the image to be toned.
The application of the sensitizer can be carried out in dim room light. When the sensitizer is thoroughly dry, the paper is exposed in contact with the negative to UV light (i.e. sunlight) and processed in a bath of running water.