Using heat and cold in the treatment of a Lakota winter count

Nancy Odegaard, Madeleine Neiman, and Dave Smith

Abstract

This paper explores the application of a temperature-based treatment methodology. Specifically, it examines how heat and cold were successfully utilized in the conservation of a Lakota winter count. While conservators have employed elevated temperatures in the active treatment of objects, the use of low temperatures has been largely unexplored.

Work carried out by Arizona State Museum conservators indicates that both temperature extremes can be used to manipulate material properties in advantageous ways. The use of cold should not be overlooked when considering treatment options. Winter counts, pictorial calendars/histories, were traditionally fabricated using mineral pigment on a hide support. During the late nineteenth-century, commercially available media as well as paper and cloth substrates increasingly replaced traditional materials. The 19th century winter count at the center of this study was drawn on the reverse (textile) side of a commercially manufactured oilcloth tablecloth. At some time after the application of the pictographs, the object was folded in half with the applied oil surfaces facing each other. While in this configuration, the count was subjected to disastrously high storage temperatures causing the oil-coated surface to soften and adhere to itself. Subsequent attempts by non-museum personnel to unfold the object resulted in tearing of the coated textile. Testing carried out at the Arizona State Museum conservation lab found the use of lowered and elevated temperatures allowed for the effective and efficient treatment of the object. The aged, the cross-linked oil coating was largely unaffected by solvent.

However, when the temperature of the surface coating was lowered using a Peltier cooler, the applied coating became increasingly embrittled allowing the fused surfaces to be cleaved along the plain of contact through mechanical action. Conversely, experimentation found that tears in the fabric were best stabilized using a heat-seat adhesive. Lascaux Textile Welding Powder was employed to tack together fibers along tears holding together where traditional stitch repairs or bulky patches could not be applied.