JOLY COLOR SCREEN

The 'Joly color screen process' is a color photography technique devised by Sir John Joly in 1895.
The plates used for the process were glass plates with fine vertical red, green and blue lines printed on them. The plate acted as a series of very fine filters, as in the other screen-plate processes. A panchromatic emulsion was coated on top of the screen. The plate was exposed through the base, allowing the light to pass through the filter before striking the emulsion. It was reversal-processed, yielding a positive transparency as to create a positive image.
When viewed through white light, a color image was visible.
The process worked. However, due to printing limitations, the lines forming the screen were rather large; therefore, they were easily visible in the processed image. The process was never marketed commercially.