Oil Print Process

Oil print by Robert Demachy - In the Grass, 1902

The oil print process is a photographic print making process that relies on variation in a hardness of a gelatin emulsion to accept an oil-based paint. When gelatin is mixed with a dichromate, it becomes light sensitive, causing some areas to accept an oil paint. In turn, other areas become hard and don't accept paint. The oil print process requires contact exposing with a negative the size of the print, because the medium isn't sensitive enough to light to make use of a projector.^[1]

References

1. http://www.larryshapirophoto.com/content.html?page=5