I was watching Elementary, Dear Data last night and I noticed that when Data realizes that something has gone terribly wrong, he leaves the holodeck with the holodeck generated paper with a drawing of the Enterprise. The paper does not disintegrate as he leaves the holodeck. If this can leave the holodeck, why can't Professor Moriarity? Indeed, the original ending to this episode according to Memory Alpha:
The original ending filmed was cut from the episode. (Star Trek: The Next Generation Companion 2nd ed., pp. 68-69) Hurley recalled, "In that ending, Picard knew how to defeat Moriarty. He tricked him. He knew all along that Moriarty could leave the holodeck whenever he wanted to, and he knew because when Data came out and showed him a drawing of the Enterprise, if that piece of paper could leave the holodeck, that means that the fail-safe had broken down. In turn, this means that the matter-energy converter which creates the holodeck, now allowed the matter to leave the holodeck, which was, up to that point, impossible. When he knew that paper had left the holodeck, he knew that Moriarty could as well, so he lied to him."
This is interesting because the whole premise of this episode and Ship in a Bottle is that Moriarity can't leave the holodeck. Moreover, the Doctor from Voyager always needs some kind of portable emitter to go places.
Given this and the water/other matter that leaves the holodeck in the linked question, why can some matter exist outside the holodeck while other matter cannot?
Is it tied somehow to the replicator - i.e. replicating a piece of paper into real matter is trivial, but replicating a human being or anything more sophisticated would be non-trivial?