Forensic document examiners employ various methods to determine the nature of ink used in creating a document. These methods range from destructive chromatographic techniques to non-destructive analysis using different light sources or microscopic observation.

The handwritings of the same individual are compared when written using different types of pens. The two handwritings above were written using different ballpoint pens whereas the bottom-most handwritings are written using a gel pen. When viewed under an infrared (IR) light source emitting radiation between 760nm to 100,000nm, the handwritings from ballpoint pens disappeared, while those from gel pen remained visible.

Figure 1: handwriting under naked eyes

Figure 2: Handwriting exposed to IR light source

This technique holds significant value in forensic contexts as it aids in identifying unauthorized alterations, such as added strokes to existing signatures or numerals on bank cheques. By leveraging such ink differentiation methods, document authenticity can be verified with precision.

For expert forensic document examination services and assistance in verifying document authenticity, consider reaching out to SD Forensic Document Services for professional guidance and support.