A systematic review of methodologies used in calculation of pen pressure in FDE

Pen pressure is an important individual characteristic of the handwriting examination whose potential has not been fully utilized. Most of the times it is overlooked by experts because they do not think it has substantial value to be of forensic significance. Generally, it is thought to be of relevance in cases involving simple and traced forgery. One of the reasons behind pen pressure being ignored by the document examiners may be a lack of technique to calculate the absolute value of pen pressure. The existing methods require specialized setup, training, and are expensive in nature and can only be used to measure relative value of pen pressure. The aim of this paper is to discuss various methodologies used by document experts and researchers in past with an attempt to quantify pen pressure and critically analyze them to bring the reader's and researcher's focus on their advantages and disadvantages. The paper also discusses prospects of future works which may include techniques that can be used more routinely in handwriting examination and can also give an absolute measure of pen pressure. In this aspect, mathematical approaches can be further explored.