In the Light

     In the spring of 2012, all of us at the museum were excited about the addition of Major Jonathan Letterman’s desk to our exhibits out at the Pry House Field Hospital Museum.  (You can see my post about the desk’s arrival here. ) 

Here is Letterman’s desk on display.

     Do you see any issues for the desk in this photo?  Note that the desk is positioned directly under a large window which is letting in a lot of sunlight.  Exposure to light can be very damaging to many materials, including the leather, cloth, and wood components of this desk.  The Pry House did have UV filtering films installed on the windows though, which were supposed to filter out 99% of the ultraviolet light coming through the glass.  

Imagine my surprise and dismay when I moved an inkwell and some papers on the desk one day and saw this.  Obviously the films in the window were not as effective as we’d thought!  This meant that ALL the artifacts in the house were probably being exposed to light levels which were much too high.

     So, I needed to find a quick and inexpensive method of protecting all the artifacts in the house from too much light.  I researched new window films, but the cost was over our budget.  Screwing brackets into the woodwork to install window blinds was also not an option in this historic house.  I started looking at curtains next.  I knew I could put them on spring tension rods which wouldn’t damage the windows, plus they were more affordable than window films or blinds.  I didn’t find much that seemed appropriate for our use in ready-made curtains though.  So, I took a trip to our local fabric store and found an insulated drapery fabric which suited the museum’s purposes.  I thought I would have to take the time to make the curtains, but Susan Yano, a staff member at the Pry House, very graciously volunteered to make them.  Thank you Susan!  The curtains seem to be functioning well, though I am looking into obtaining some blue wool standards to better monitor the displays. 

Blue wool standards, or blue wool scales are used to monitor light exposure in display areas.  Usually one side of the scale is covered so that the light cannot affect it, then when the card is checked later any fading on the uncovered side is apparent.  If there is noticeable fading on the card, I’ll know I need to take stronger measures to block the light from the artifacts.

You can see here that the curtains block a lot of the sunlight from the artifacts, but still let in enough light for visitors to view the displays.  For now, I'm declaring the curtains a success!    

Photos courtesy of the National Museum of Civil War Medicine.