Early real photo postcards are small by their very nature and since most were contact printed, not enlarged, there is no visible texture.
Some real photo postcards were used for advertising or sold to the public at stores.
The key is silvering is an aging process and appears after decades.
The presence of silvering is strong evidence of a real photo postcards old age.
Earlier cards were called ‘Private Mailing Cards.’ Only the address was allowed to be written on the back of the card during Post Card Era. Divided Back Era ( ) Postcards with a divided back began March 1 1907.
The address was to be written on the right side and the left side was for writing messages. The early images were ‘full bleed,’ meaning that they went all the way to the edge of the card.