In quantum mechanics, the observer effect postulates that a photon’s status as a particle or a wave is determined by observation rather than the photon’s intrinsic qualities. The observer effect can also provide a useful conceit to explore the ways a conservator’s perception can transform an object’s context, and lead to different treatment choices that may significantly alter the object. The recent conservation of a man’s silk suit from the 1740s provides an opportunity to (re)examine choices made by eighteenth-century tailors and previous conservators through their historical perceptions of the suit. The suit was accessioned by the Museum of the City of New York in 1938. Its many repairs reflect the different assumptions associated with clothing, costumes, and collections. The recent conservation included mechanical removal of flaking adhesive from a previous treatment, and utilized stitched underlays to consolidate and support tears in the silk suit. By acknowledging the effects of observation, we can better evaluate the methodologies used by conservators and seek ethical treatment choices for an object’s current needs that balance an understanding of its past and anticipation of its future. This paper will explore the impact of historical and contemporary perceptions of the same suit on treatment choices.