Each of these images is slightly wider than the standard postcard dimensions and were produced in the era just before the authorization of the private postcard when demand for mechanically reproduced coloured images exploded.

These "photochrom" or "chromolithograph" pictures are all the product of the Detroit Photographic Company, a early adopter of a Swiss technology for mass producing colour images coloured from black and white photographic originals.

There are several online collections featuring the Detroit Publishing Company images including the Library of Congress and the Henry Ford Museum