Dating old photographs postcards liquidating a business
Cards previous to that had to have the Private Mailing Card Statement. There was often a statement that said "this side for address only." The postal service started allowing the use of divided back postcards in March of 1907.
So, if your card is marked "Private Mailing Card," is dates from 1893 - 1901. A divided back postcard (example 3) has a line down the middle, or some other indication that one half of the back is for the address and the other half is for a message. If your postcard has an undivided back, it is from 1907 or earlier. during World War I in order to save ink and estimated to have saved 20% more ink.
But even here the effect is more of a softening of detail than a observable texture.
Early real photo postcards are small by their very nature and since most were contact printed, not enlarged, there is no visible texture.
Collotypes, which provide the finest detail of all printing methods are sometimes confused with real photo postcards.