books than an acid-free backing board and Mylar sleeve. Storing a comic as a computer file (scanning and saving the comic as a comic book file or .cbz/.cbr) is also an option, allowing those without access to the comic itself a chance to see at the least the story for themselves. However, as with other digital means of storing media, this also allows for the possibility of copyright infringement via unauthorized digital distribution, such as peer-to-peer file sharing networks. Subscription crease A subscription crease describes a specific flaw in the condition of a comic book, particularly a crease through the entire book running from top to bottom. It is a term commonly used by comic book collectors. When comic book publishers began mailing comics directly to monthly subscribers they would simply fold the comic in half and stuff it into a standard #10 business envelope. This method was expedient and cost effective – the comic book business survived on razor-thin margins – but resulted in a clearly visible line running from top to bottom of a comic. The "memory" factor inherent in paper assured that this crease would be visible forever. Consequently, collectors, who prize condition, consider this a defect that lowers the desirability of a particular issue. This practice faded away in the early 1970s when publishers found a marketing opportunity in mailing comics in larger envelopes, unfolded. Hence the appearance of in-issue ads touting that monthly comics were "Mailed flat!" Related collecting Collecting original art is the collecting of the artists' production pencils and inks used in the creation of comic books. Unlike mass-produced comic books, there is only one piece of original art for each individual comic book page or cover. A Mike Zeck original page of the 1984 Marvel Superheroes Secret Wars, showing Spider-Man wearing his black suit for the first time, was sold by Heritage Auctions in January 2022 for over $3 million. As of 2022, it is the most expensive page of a comic book ever sold. List of comic collections Many private collections of comics exist, and they have also started to find their way onto the shelves of public libraries. Museums and universities with notable collections of comics include: Allen and John Saunders Collection at Bowling Green State University's Popular Culture Library. British Comics Collection at The British Library. Comic art collection of Michigan State University. Comic Book Research Guide of The