Bas relief - advanced darkroom technique

Creative darkroom photographers who like to experiment should get hold of a pack of lith film. There are several interesting techniques you can try including his one - bas relief.
Lih film is a very high contrast film that reduces the tonal range so that primarily just black and white tones exist with minimal grey. By sandwiching and contact exposing full tone negatives you can create high contrast photographs.
Bas relief is where a high contrast negative and positive are sandwiched together very slightly out of register.
To attempt this you need a pack of lith film (it's sold in 5x4in sheets) and a pack of line film also sold in 5x4 sheets along with the usual collection of processing accessories such as trays, running water, thermometer, graduates etc that are mentioned in our basic darkroom guides in the archives and an enlarger to print the results. Lith film, unlike conventional negative film can be handled in red safelight conditions so you can see what's going on.

3 When dry, make a contact negative using the lith film (again make a test strip first). My exposure was f/8 for six seconds. This then needs processing in special Lith developer that comes in parts A and B that are mixed together to make a working solution.

4 When dry make another contact on lith film to produce a positive then process, wash and dry.

Tips

• Make sure the negative you use is free from dust and scratches as these will be highlighted in the bas relief.
• Choose a subject with plenty of strong, well-defined lines such as tree branches, fences, ivy, cars, boats etc.

You can contact print the lith sandwich with another sheet of lith film to make a negative that can then be used without trying to keep the pair in register to produce a lovely black image with a white outline bas relief.