Systematic study of a method to determine the sequence of crossing lines on stamping before writing.

Determining specific line-crossing sequences has always posed a challenge for document examiners. Interactions between pen ink and stamp seal ink can be complicated and changeable due to the many seals and writing inks available in the market. This study determines the line-crossing sequence of stamping before writing by observing the influence of seal ink on pen writing. The results of examining four types of pens and six types of seal ink crossings reveal that assessing the completeness of writing strokes can determine sequencing. Different ink types interact to produce different phenomena. In addition, time interval and pen structure affected the interaction between two inks in a crossing. A 70% accuracy rate was achieved in a nationwide blind test, which will be discussed in this article.