[Process Materials Corp., NJ] A brand name for a marking pen containing a pH indicator dye. The Archivist's Pen contains Bromcresol green indicator solution. When a small dot of ink is applied to a dampened paper, it will produce a color that is an approximate indication of its acidity or alkalinity. A pH greater than 5.2 gives a blue color while a pH of about 4.5 is green and more acidic levels (pH less than 3.5) are yellow. The dye residue leaves a permanent stain on the paper and should not be used on a work of art. However, it may be useful for matboards, lining paper and hinges (King et al 1970).
Resources and Citations
- J. Miller & E. McCrady, "Comparison of pH Pens on the Market" Alkaline Paper Advocat Vol. 3, No. 5, Nov. 1990.Link
- A.King, A.Pelikan, W.Falconer, "The Use of the Archivist's Pen and Universal pH Solution for Estimating the Surface pH of Paper" Studies in Conservation, 15:63-64, 1970.
- Marjorie Shelley, The Care and Handling of Art Objects, The Metropolitan Museum, New York, 1987