Ballpen writings exhibit certain distinctive characteristics due to the physical properties of the ball mechanism and ink. These include:
Features such as darker double tracks and dark flow back are not exclusive to ballpen writings and may be observed with other types of writing instruments, depending on ink viscosity and pressure.
| LIST I | LIST II | ||
|---|---|---|---|
| A | If two writings are by a single per son | I | may result from influences as the writing system studied etc. |
| B | Personal peculiarities, many of them in inconspicuous details | II | constitute the back bone of an identification |
| C | Class characteristics | III | then no fundamental differences should exist |
| D | Individual characteristic | IV | distinguish the writings of two persons |
Match Fibre with Application.\[\begin{array}{|l|l|} \hline \textbf{LIST I} & \textbf{LIST II} \\ \textbf{Fibre} & \textbf{Application} \\ \hline \hline \text{A. Silk fibre} & \text{I. Fire retardant} \\ \hline \text{B. Wool fibre} & \text{II. Directional lustre} \\ \hline \text{C. Nomex fibre} & \text{III. Bulletproof} \\ \hline \text{D. Kevlar fibre} & \text{IV. Thermal insulation} \\ \hline \end{array}\]