In 1975 Marvel over here in the UK (later to be formally called 'Marvel UK') carried out a format experiment with a couple of their titles.
The Titans was a weekly comic that featured The Inhumans, Captain America, Nick Fury, The Sub Mariner and Captain Marvel.
The page was turned on it's side and managed two original comics pages per black an white reprint page.
I don't think it ran for long but I remember thinking it was pretty cool at the time.
Below are some of the pages to illustrate what I mean, along with a great advert for a Marvel Art Exhibition at the very high brow London Institute of Contemporary Arts in The Mall.