For the Drawing Room wallpaper investigation, Dr. Buck took a large number of samples from places where she knew from experience might hold fragments of wallpaper.  Specifically, Dr. Buck concentrated on a region found above the triple-sash windows.  This location was selected because it was not visible to someone standing in the room and so would be a likely place to find an overlooked fragment of wallpaper stuck to the trim.  Amazingly, when Dr. Buck processed her samples from above the window she discovered one sample that contained a microscopic trace of wallpaper overlaying a layer of ca. 1812 trim paint.  Because the paper fragment was so closely associated with the ca. 1812 paint, it meant that it was almost certainly the paper that hung in the room during President Madison’s retirement period at Montpelier.