Proper noun
Paget process
English Wikipedia has an article on:Paget processWikipedia
An early colour photography process using two glass plates: a colour screen plate, with red, green and blue filters, and a standard black-and-white negative plate.
The additive RGB model and variants such as orange–green–violet were also used in the Autochrome Lumière color plates and other screen-plate technologies such as the Joly color screen and the Paget process in the early twentieth century. Source: Internet