I've always got an eye out for interesting and beautiful playing cards, and these to my sensibilities are very much both of those, though a bit hard to photograph well due to the sheen. The 1903 deck, produced by The Cincinnati Game Company for educational purposes, consists of 55 cards representing various geometric stapes, with a complete instruction book detailing various ways to use them. I find the minimalist pale minty green shapes super satisfying just to look at, reminding me of watercolored geometric equations in antique school notebooks, and the back are pretty beautiful too.

Box measures 3 5/8" x 2 11/16". Complete deck of 55 cards, which are in very good condition. Box shows some wear as pictured.