Today's deck isn't difficult to
date. The date is on the backs: 1937. The deck was published by Emil Jensen as
"Jubileums Bridge Kort" to commemorate the 25th anniversary of King
Christian X's reign in Denmark. It's a double deck with the portrait of
Christian X on the backs of one deck and -as shown here- with his wife, Queen
consort Alexandrine of Mecklenburg-Schwerin, on the backs of the other deck. The
pattern of the courts was already published as Warburgs Bridgekort (also by Emil
Jensen) since around 1930. Both editions have plain aces and were printed by De
La Rue from London.
I've added a close-up of the back. Not because I've suddenly become an offset fan, but because I was intrigued by the finishing of the backs. The front of the cards is smooth, but on the back a herringbone patterned finish was applied. Never seen that before. But as you can see it's even worse for the design than the air-cushion finish of the modern decks, when you want to take a closer look.