The Process

The platinum process, like many of those alternative processes from the late 19th and early 20th centuries, requires a negative the same size as the final image. This is because the platinum solution is only sensitive to ultraviolet light.

In the past, the usual method was to start with the original negative and make a small film positive from it. This was then enlarged onto another sheet of film to the dimensions of the final image. Until technology made it possible to make digital negatives, this was the only way of making large negatives, other than by photographing with a large format camera. Not only was it time consuming, but it involved much testing to get a good negative. Eventually, many of the films that were suitable for this method were discontinued, and printers turned to the computer for alternative methods.

Currently, I’m using an inkjet printer to make the final negatives. The original film is scanned and the work done in Photoshop, using any of the methods I would have used in the darkroom, such as burning, dodging, cropping etc. Then, I output the file using an inkjet printer and film rather than paper. This results in a contact negative that can be printed in the darkroom in platinum.

The platinum print is made by hand-coating with a brush, a sheet of paper with light sensitive platinum and palladium chemicals. The optimum print is obtained by using a combination of the two metals. A higher proportion of platinum will result in a cooler image, while more palladium will give a warmer image. The sensitizer is dried and the inkjet negative placed in contact with the paper. This sandwich of paper and film is then placed in a vacuum frame to ensure complete contact, and exposed to ultraviolet light. The paper is removed from the frame and placed in the developer, where the image appears instantaneously. The print is then rinsed and placed in several successive clearing baths to remove unwanted chemicals and metals. Finally, the print is washed and dried.

Assuming the paper used is of a high quality and that the processing sequence is carried out correctly, the resulting print will have archival properties far in excess of any other photographic medium, making it desirable to collectors and galleries.