Inhomogeneity and Aging of Ballpoint Pen Inks Inside of Pen Cartridges

Abstract Inhomogeneity and aging of ballpoint pen inks inside of cartridges, particularly near the tip of a pen, were studied by HPLC (high pressure liquid chromatography). No indication of aging in terms of changes in dye composition inside of a regularly used pen was observed. Ink entries on paper were, however, found inhomogeneous concerning concentration of phenoxyethanol, a volatile compound commonly present in ballpoint inks. Detectable and sometimes considerable aging of inks near the tip of cartridges not used for writing for many years was observed. Both evaporation of phenoxyethanol and aging of cationic dye mixture were detected at the start when writing with such pens. The consequence of this finding for ink examination, both ink comparison and ink aging, is discussed.