Establishing Sequence of Inkjet Printer, Laser Printer and Writing Ink Strokes using Scanning Electron Microscopy (SEM)

Abstract

The aim of the present study is to determine the sequence of laser printer, inkjet printer, and writing ink (ball point pen ink, gel pen ink, pilot pen ink and fountain pen ink) strokes using a low voltage (1kV) scanning electron microscope (SEM). Intersections were prepared using an inkjet printer, laser printer, and writing instruments on copier paper. About 1cm2 of intersection was cut using scissors and mounted to the probe stage of the SEM using double-sided tape. Each sample was analyzed at different operating parameters. The results were evaluated on the basis of continuity and iscontinuity of strokes at intersection point. It was possible to determine the correct sequence of printer strokes versus other writing instruments’ strokes; inkjet printer stroke versus fountain and pilot pen ink stroke; however, inconclusive results were obtained in the case of inkjet printer strokes versus ball point pen and gel pen ink strokes. The ffectiveness of this technique was determined by analyzing the exact sequence of blind samples. An SEM could be used as mplimentary tool with other optical methods to examine the sequence of strokes.

Keywords

• forensic science
• forensic document
• sequence of strokes
• inkjet printer strokes
• scanning electron microscope