The surface pH measurenient and deacidification of prints and drawings in tropical climates

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Publication Type:

Journal Article


Boustead, W.M.;


Studies in conservation, Volume 9, Number 2, p.50-58 (1964)


Australia, Australia (New South Wales), Australia (New South Wales–Sydney), bleach, calcium hydrochlorite, chloramine t®, deacidification, drawings, Lissapol®, Oceania, paper, pH, prints


The acquisition of a direct reading pH meter equipped with standard reference and flat head electrodes enables the Conservation Department of the Art Gallery of New South Wales to carry out quick pH measurements on prints and drawings. The old method of cold extraction was both time-consuming and usually not possible to carry out owing to the destruction of the sample. Measurements conducted on a recently acquired collection (1962) of valuable old prints indicated that the majority were highly acidic. The prints were subjected to a deacidification treatment based on the Barrow process which raised the pH to an average of 8.5. If properly carried out no "chalking" or loss of values is apparent on even the most deeply etched prints. Colored lithographs are also unaffected. The process is now routine procedure for all prints and drawings requiring any form of restoration. Abstractor's note: Tests carried out recently (3% years later) on one-third of the prints originally treated revealed no appreciable drop in pH values. W.M.B.