Autochromes Lumière

 

Dusting

Dusting in Four Steps
The Autochrome began with a dusting of coloured starch, followed by another of black carbon, and then finally by two applications of talc. In the first step, the starch mixture was sprayed across the surface of the varnished plate, which acted as a sticky coating that secured the fine layer of starch in place. This was the essential step in realising the processes of additive colour synthesis. After a brush had delicately pushed the powdered mixture onto the varnished surface, assuring that it adhered and eliminating any excess particles, the same operation was repeated with the powdered back carbon to fill in the spaces left between the starch granules. Finally, two applications of talc were applied, which eliminated any excess carbon and prepared the surface for the lamination.