This is a vintage 1966 Donruss Iron Man #22 trading card from the Marvel Super Heroes 66 card set.  The card is entitled "When did you first notice those stomach pains?" The back is a plain color.  The original set featured 11 cards each for 6 super heroes (Iron Man, Daredevil, Spider-man, Captain America, Thor and Hulk).  The set is considered the first trading card set to feature the Marvel superheroes.   My husband got the card in the 1960s in a pack of gum.  Its in very nice condition but not graded professionally. (See photos)  The card measures about 3.5" x 2.5".