A study for establishing the sequence of superimposed lines: Inkjet versus writing instruments

Intersections of inkjet strokes of different color (black, red, green and blue) with ballpoint ink or gel pen ink or fountain pen ink strokes each of different color (black, red, green and blue) were examined under stereomicroscope and digital microscope. The exemplars (25,920 intersections) were prepared on three types of paper at three time intervals. Stereomicroscope proves very successful in determining the sequence of ballpoint ink or gel pen ink of different color and inkjet stroke of black color only. It also helps in determining the sequence of intersections of fountain ink strokes (all color) and inkjet strokes (all color) with highest success rate (100% correctness). The digital microscope is not useful in determining the order of inkjet strokes and ballpoint ink or gel pen ink. These observations show that for the correct order of sequence, intersections magnification as well as good angle of illumination is required.