Here are some more Mark 1 Superman birthday cards which I featured last year in a post here. In 1978, Mark 1 released a series of 40+ different greeting cards featuring the DC superheroes. Each of the cards is about 4-1/8″ wide by 9-1/4″ high and is numbered on the back. Most feature embossed designs. I don’t know who the original artist is on these… some of them look vaguely like the work of veteran DC artist Kurt Schaffenberger, but it wouldn’t surprise me if an unknown freelance illustrator was using his work as reference.
The jokes on these are awfully corny as greeting cards go, but they’re also a lot of fun and not terribly difficult to find.