Treating a Previously Bleached Artwork on Paper

Abstract

The case study describes the treatment of an etching that had been bleached in the past with 4% hydrogen peroxide and had subsequently suffered extensive colour reversion in the form of foxing and overall discolouration. Staining was most likely caused by the action of hydrogen peroxide on previously unnoticed iron particles in the paper. The print now underwent treatment to stabilize the damaged paper. The print was immersed for 50 seconds in 0.1 M hydrochloric acid HCl (pH 1.1) to extract as much as possible of the iron contamination from the paper; this was followed after rinsing steps by complexation of remaining iron ions through immersion in a calcium phytate solution (1.75 mmol/L, pH 5.3). The treatment, which included extensive rinsing, significantly diminished the foxing stains. No further bleaching treatment was conducted to diminish remaining stains so as not to risk further destabilization of the pre-damaged paper.