Diego and I are currently working on a new project that will be a folded ("double") QSL card for European divisions.
Later, we will start working on a WORLD QSL.
We will soon publish some QSL preview / sample that you will be able to comment.
We can already tell you that there will be six confirmation boxes in these QSL cards, so the card will be perfect to confirm your QSO with IOTA tours, island tours were you worked several references.
Great idea, Diego ! Saves QSL cards, shipping weight, and still better than sending a log sheet !