The Gallery & Collections Coordinator at an area university recently brought in a set of 14th century engravings created by Hans Sebald Beham. Like many works of art in need of the care and attention of a skilled conservator, these pieces were attached to an acidic backing board with dry mount tissue. The paper was becoming yellowed and acidic, and there was significant planar distortion & cockling present. The prints were detached from the backing board carefully, and treated via immersion in solvents to remove the dry mount tissue and damaging tapes applied to the back of the engravings.
Dry mount tissues can be stubborn and difficult to remove. There are also a variety of them that have been in use over the years, and the manufacturers change their proprietary adhesive formulations frequently. Care, skill and patience are often required to determine the correct course of treatment to remove them and repair the artwork. After immersion treatment, the artworks were treated with chelating agents to reduce the staining, yellowing and soluble acidic degradation products present in the paper. The paper was alkalized to prevent further deterioration and embrittlement. Once treated, the engravings were humidified and flattened in preparation for archival framing.