Regardless of what you may have been told, other materials are not archivally safe to store your posters in. Plastics, vinyls, and other storage materials slowly oxidize releasing harmful acids which slowly eat your posters alive...
Mylar-D is a storage material specifically developed for the long-term storage of historically important documents. It is the same archival material in which the Declaration of Independence and the Magna Carta are stored and is used by leading museums worldwide. While other materials may not begin to noticeably damage your posters for 2, 3 or even 5 years, Mylar-D is considered completely inert for up to 400 years.
Don't Trust Your Valuable Posters To Anything Else.
