qnli question: What was affected by the increasing use at Marvel of crossover stories between comic characters? sentence: Marvel earned a great deal of money and recognition during the comic book boom of the early 1990s, launching the successful 2099 line of comics set in the future (Spider-Man 2099, etc.) and the creatively daring though commercially unsuccessful Razorline imprint of superhero comics created by novelist and filmmaker Clive Barker.