Although this card from the Netherlands did have art stamps on it, I had to go to France to find the first Madonna and Child stamp.
It commemorates the 500 years since Rafael painted it in 1512/13. The original hangs in the museum in Dresden.
The Royal Mail quite frequently uses art on stamps, particularly around Christmas time. I have a set of PHQ (postal headquarters) stamp cards from 1991 which are taken from a 14th century manuscript kept in the Bodleian Library in Oxford.
These are just two of the set. I love the colour and form, but if you look closely at the faces, they do look a little odd though possibly more "real". I prefer them to some more recent versions.
As I said, the original postcard did have art stamps on it too, commemorating Rembrandt
And another by Vermeer, that almost everyone will recognise thanks to the recent film, Girl with a Pearl Earring.
This is a post for Sunday Stamps, now hosted by Violet Sky at "See it on a Postcard!"