Andre, my office is located in the exhibits production branch of a museum....don't confuse exhibit materials, even on display in a museum (not talking about art museums here....) for being archival necessarily....alot of times they are just components to an exhibit, like graphic panels or a diorama....uhm, one reaso why aluminum is used is for durability...we've used it for mounting very large mural sized prints, that would be on display for a long time...however, when we've changed out some part of an exhibit, we tend to trash these things in the process...because they're often glued to the walls or the backs of cases, or put on with a 100 feet of double stick foam tape that rips the heck out of everything when you remove them.....if they do survive, they wind up in storage areas gathering dust. The film though, sits safely in a controlled storage room.....