Not postally used, and no other information on the card to give us an exact age. Domestic rate for post cards was 1 cent until 1952. We could not find a record of international rates, but with the rate to Canada also being 1 cent and rate to the rest of the world being two cents, we assume that this was considerably earlier than the 50's. Card has moderate corner wear. The number 100 is written in pencil center top of the back.