Postcards
The first commercially produced card was created in 1861 by John P. Charlton of Philadelphia, and it was just a piece of paper with borders, without any images. Then, the first known printed picture postcard was created in France in 1870 at a training camp for soldiers called “Camp Conlie” by Léon Besnardeau. These postcards contained images of the armament and were like “souvenirs” from the Conlie Camp but it seems that there was no space for stamps and there is no evidence that they were ever posted without envelopes. The first known postcard in which the image was like a souvenir was apparently sent from Vienna, in 1871 (wikipedia).
After that the number of these beautiful souvenirs just kept growing, and now we have so much variety to choose from. Actually, these days I wonder if it’s not a little old fashioned to send postcards… I know I didn’t send any from my holidays over the last few years. Maybe I’ll try to send some postcards from the next beautiful place I visit, but I won’t make any promise since the virtual postcards are a lot easier to send!