Autochromes Lumière

The First Varnish

Preparing the Glass Plate
A plate of glass, the thickness of which could vary between 0.9 and 1.8mm, was cleaned and cut to a format of 20x84cm. These dimensions allowed one to meet the specifications of the various standard formats of the time, up to the maximum for commercialised plates, 18x30cm. Formats of up to 24x30cm have been found in some collections, but they were most likely the result of special manufacturing.

Spreading the Varnish
The glass plate was covered with a latex-based adhesive layer, which Louis Lumière described as the tacky varnish. This would be called the "first varnish." During this process, the varnish was poured onto the glass plate , after which it was rapidly dried by hot air.