Every person possesses a unique handwriting manner. While learning to write at school a child trains elements of letters following the traditional pattern thus forming writing skills. During this process a set of dynamical stereotypes of reflexes are forming. But later these dynamical stereotypes of reflexes are influenced by other dynamical stereotypes. In the process of writing the whole cortex of the leading hemisphere participates in the act of writing the number of influencing dynamical stereotypes is immense thus building a basis for a unique handwriting manner.
The study of handwriting manner is carried out by forensic document examiners and graphologists. People have been studying handwriting manner for about 400 years. In 1622 Camillo Baldi published a book “Treated how, by a letter missive, one recognizes the writer´s nature and qualities” that is believed to be the first known essay on the subject. However the first to study the handwriting manner is believed to be Abbot Michon who founded the society of graphologists in 1871 and published several works and gave scientific basis to the handwriting analysis. His work was continues by his pupil, J. Cr´epieux-Jamin, who distinguished 7 fundamental characteristics of writing: speed, pressure, form, dimension, continuity, direction, and order.
While using TEOFRAST a tablet captures such characteristics as velocity, acceleration, slope, pressure (if applicable) and a sophisticated algorithm processes these characteristics. After processing the graphical image of the signature is deleted and the digital portrait of writing dynamics is formed and saved in a database.
Every time you sign the dynamics of your handwriting changes a bit and the portrait of writing dynamics changes as well that is why the digital portrait (sample) cannot be forged as it is never the same.