The Tattoos & Transfers Gallery
These "stamps" appear to be transfers or tattoos as they were known long ago. They could be transferred onto a persons skin to look like a tattoo or transferred to the paper as well. I think in these cases children were just looking for anything to transfer them to and they had worthless baseball cards with generic ads for cigarettes on the backs. Some of these tattoos are amazing and they are all multi-colored as opposed to their single color stamp counterparts.