Practical Considerations for Conservation Bleaching

Abstract

This article was written as a practical handbook and literature review for conservators who are considering the chemical bleachi of cellulosic artifacts, especially paper. The bleaches discussed fall into the two classes of (!) oxidizing agents, i.e. the hipochlorites. chlorite/chlorine dioxide and stabilized peroxide, and (2) reducing agents i.e., borohydrides and the sulphur-containin compounds. The topics covered include the factors to consider before bleaching, e.g., the effect of the bleaches on chemical 0 r physical damage to the fibre, bleaching efficiency, and colour reversion; conservation and curatorial considerations; methodology for making up bleach solutions, as well as the handling and applying of the bleaches; working properties of the individual bleaches- and washing, neutralization, alkalization, and anti-chlor procedures carried out within the context of an overall treatment plan that includes bleaching. An emphasis is placed on explaining the process of making the conservation decisions relating to conservation bleaching treatments.