A trade paperback is a collection of individual comic books bound together by the publisher and sold separately from said individual comic books. Usually the trade paperback forms part of a longer series (for instance, Preacher or Scud: The Disposable Assassin) that has a coherent plot, although sometimes a trade paperback can encompass the entirety of a particular title's run (such as Unknown Soldier); this mostly depends on the length of the title, although it can also depend on the publisher's predilections, as well. Although the trade paperback and graphic novel are often confused due to their physical similarities, the primary difference between the two is that the trade paperback is first and foremost a collection of previously released material in less fragmented and usually more cost-effective form, while a graphic novel can be composed of original material and is often thematically more limited by the audience's preconceptions about graphic novels (see graphic novel writeup by Elendraal for a prime example thereof).