1 INTRODUCTION

WALLPAPER, from the perspective of the architectural conservator, is an integral part of the interior decoration of a historic building. Used in combination with paint, molded woodwork and plaster moldings, wallpapers are hung to give a room's wall and ceiling surfaces color, texture and a decorative pattern. Most often historic wallpapers are applied directly to a room's plaster walls and ceilings. This direct application establishes the relationship of the wallpaper to the other architectural elements in the room—woodwork and plaster moldings. It also creates a physical bond between the wallpaper and the plaster wall surfaces, so that structural deterioration or environmental factors that result in damage to the substrate also cause damage to the historic wallpaper. Recognition of the interdependency of the wallpaper and the structure in which it hangs is crucial for successful wallpaper conservation. This interdependency requires that architectural conservators and wallpaper conservators collaborate so that conservation treatments to the wallpaper and the structure are compatible.1 Only if the wallpaper is a small fragment that will not remain in, or be returned to, its original location in the historic structure should it be treated as an isolated object.

Architectural conservators in their work with historic buildings use early wallpapers in two principle ways—to restore an interior room to its appearance at a specific time in the history of the structure and to help document alterations that have been made to a room. This work involves two levels of wallpaper conservation—the conservation of entire rooms or large areas of historic wallpaper and the conservation of small wallpaper fragments. These levels of conservation have different treatment objectives, raise different practical and philosophical questions, and require varying degrees of interaction between the architectural conservator and the wallpaper conservator.