The effects of aqueous light bleaching of a naturally aged, 100per thousand cotton rag, gelatin-sized paper on the subsequent aging of that paper have been investigated. Effects of exposure to various control conditions were compared with those due to aqueous light bleaching. Physical properties of all papers were monitored by measurement of surface pH, optical properties, stress-strain tensile behavior, and presence of sizing. Measurements were made before and after treatments and after artificial aging at 90°C and 50per thousand RH for 20 days. An unsized filter paper, made from 100per thousand cotton fibers, was exposed to identical conditions, and the same properties were measured. For the gelatin-sized paper, aqueous light bleaching resulted in less color reversion after artificial aging than did exposure to any of the control conditions. However, the sized paper specimens exhibited significant change in tensile properties. Similar responses were also observed in controls that were immersed in the dark. The changes noted are likely to be attributable to immersion temperature. All paper specimens were significantly embrittled by artificial aging. The changes in tensile properties of both types of papers upon aging did not appear to be influenced by exposure to light during the bleaching procedure. -- CAL -- CAL -- SCMRE