In our Lunder Conservation Center, our fellow, Im Chan, has been working for months assessing and treating a group of prints and drawings by William H. Johnson. Ms. Chan removes any potentially damaging materials that were added after the artist finished the piece. With Johnson's Boy's Sunday Trip, the drawing was previously adhered to an acidic paperboard backing (an acidic backing can result in a deterioration of the artwork).
When she began removing the backing, she discovered a surprise on the work's verso (back side): a previously unknown drawing. We're not yet sure what the purpose of this drawing was. Perhaps it was an early draft of a new mural. Future research remains to be done.