Dating foreign postcards difference relative dating absolute dating

Today there are many real photo postcards of unknown origin and date.

A studio sometimes grew to the point where additional photographers were hired but all the photographs produced were published with the original photographers name.At other times a studio might buy out the negative inventory of older photographers and reprinted their images under the current studio name.Collotypes, which provide the finest detail of all printing methods are sometimes confused with real photo postcards.But even collotypes will exhibit a discernible grain when magnified.In printed images the grey areas are usually made up of black marks that are spaced to create the optical illusion of greys.

Though most of us today are familiar with the concept of photo grain, this is mostly because we have experienced very large prints made from small 35mm negatives.If the name appears on the photo itself, it is because the negative was scratched into or written upon but it could have been printed at any time.Some companies were still printing real photo postcards in the 1970’s from negatives taken in the 1890’s.The simplicity of the process made it very attractive to amateur photographers.Printing out papers fall into two categories, those coated with metallic salts, and those with coated with an emulsion.- This process was invented in 1842, but its first known use for a postcard was in 1888.