Colored photo from the archives of the Library of Congress.
We offer you to plunge into the Rome of the late nineteenth century through the collection of photo postcards from the archives of the Library of Congress.
Images were obtained through the use of photochromic process, invented in the 1880’s, an employee of the Swiss publishing house Orell, Gessner, Füssli Hans Jacob Schmidt.
To create the final image from the original negative to create some lithographic printing plates for each color: the number usually ranged from 6 to 15 depending on the required color accuracy.
