This pamphlet was on exhibit for way too long. Even with UV filtered light in the exhibit cases, paper documents can get bleached. By "bleaching", I mean the yellowing apparent on the blank margin of the paper. The white-ish stripe in the first printed column is where the Mylar strap held the pamphlet open and protected the paper from the light. Not all of the items in the exhibit show this level of damage, so I'll be reviewing the lighting and other exhibit conditions that could be affecting this particular piece.
Exhibits can be tricky. They're a wonderful opportunity to showcase your collections, bringing out items that the average visitor to your institution may not know about and yet you are exposing your collections to potential damage that you may not be aware of until too late.