If you collect everything an author wrote (or, in my case, everything they wrote which has been published as a separate items), you can end up with things that stray fairly far from what most people think of as “books.” Here are two recent acquisitions that may cause more than one collector to go “What the hell?”
Gaiman, Neil, with David McKean. Mythological Creatures. The Royal Mail, 2009. First edition folded broadside, legal-paper sized printed cardstock, two-sided, with six stamps in attached Mylar pouches, Fine. Collectable stamp folder with six mini-stories by Gaiman, one for each mythological creature on the stamps, with Dave McKean art. An odd item I only recently became aware of, and one that may frustrate Gaiman completists a few years hence…
Swanwick, Michael. Tumbling. Dragonstairs Press, 2013. First edition micro-chapbook original, 3″ x 2 3/4″, #10 of 50 signed, numbered copies, Fine, new and unread. Bought from the author at the 2013 San Antonio Worldcon. Dragonstairs Press is Swanwick and his wife, and they do short run Swanwick chapbooks. This one is even a shorter run than their usual 100 copies.