Line Direction Determination of Ballpoint Pen Ink Writing

Determining the direction in which written lines have been executed is an important part of the work of the forensic document examiner. This information can be of key importance in the comparative examination of questioned and specimen signatures and handwriting and also in determining the presence of altered writings (Fryd, 1975).

The purpose of this paper is to report on an initial assessment of the reliability of a documented method of determining ballpoint pen ink line directions by observing the preferential build-up of ink on the upstream side of paper fibres.

During 2013 and 2014 document examiners with several organisations in Australia took part in a blind trial. Each examiner was asked to determine the direction of writing of forty short, straight lines written with two black ink ballpoint pens. The samples were prepared so that other direction information was excluded. Participants provided an unqualified or qualified determination or an inconclusive result for each line. Examiners’ results were assessed to determine the overall reliability of the method. Factors that appear to allow a confident determination and factors that detract from making
a determination are discussed.