Kodak paper dating guide
This too is not foolproof for many publishers had large stocks of photo papers using them for decades after they stopped being manufactured.
NOTE: There were many other photo papers manufactured in addition to those listed on this page, and even these could be made in different finishes from matte to glossy.
Observing this shiny crust, no mater what the color, is a quick and sure way of telling if you are looking at a real photo.
A common problem with real photo postcards is that they are often devoid of any descriptive text.
Light energy alone, usually from the sun, reacted with the light sensitive chemicals on the paper’s surface to produce an image.
They only needed to be fixed to preserve the exposed image.
This gives these images a very matte look not normally associated with photography, and making some easy to confuse with collotypes.This could go on for generations, and it is not uncommon to find the same photograph attributed to three different artists.While today this would lead to lawsuits, copyright was uncommon and rarely enforced at the turn of the 20th century.Many other brands of photo paper were also manufactured in Europe but rarely left the continent.The very first photographs made were on printing out paper.