Trade Paperbacks are a great thing for comic book readers. Issues that were out of your range because you're not rich are accessible through them. But much like how some shows are unaccessible on DVD (if not an episode or two), there are some issues that may not see reprints anytime soon (or at all). Which issues do you know of that can't be reprinted? 1. What If? #13 (The story basically asked what would happen if Conan The Barbarian ended up in the modern age): To my understanding, Marvel doesn't have the liscense to reprint any Conan based comics or issues that may feature Conan. As such, this issue was skipped in the What If? Classics TPB. 2. The Ren & Stimpy Show #6: To my knowledge, companies that loaned out their liscenses to comic book companies can reprint their material provided they find another publishing company (or I'm at least guessing given that IDW has reprinted Star Trek comics that Marvel published). So if Nickelodeon wanted to reprint their Nick comics, they probably could. But unless they were reprinted through Marvel, this Ren & Stimpy issue would be left in the dust due to the appearance by Spider-Man.