Manufactured by Sanger-Shepherd & Co., Ltd., London, England
These devices were invented soon after the autochrome came to the market and helped to eliminate the problem of "frilling". Frilling happened when the emulsion separated from the filter layer along the edges of the glass and was generally caused by poor methods of agitation.
Though a consistent problem among many amateur photographers, it was also a short-lived problem among even among the most sophisticated autochromists including Edward Steichen.
