Kinematic Sequencing
A genuine signature is executed as a fluid, unconscious motor program. A forgery is a conscious drawing process. Kinematic sequencing examines the physical evidence of this difference.
The Speed/Accuracy Trade-off
Fitts's Law states there is an inverse relationship between the difficulty of a movement and the speed at which it can be performed. Forgers must slow down to achieve spatial accuracy (copying the shape). This slowing leaves distinct markers in the ink trace.
Genuine Signatures Show:
- High velocity (smooth, sweeping lines)
- Tapered start and end strokes (pen flying onto/off paper)
- Variable pressure (heavier on downstrokes)
- Fluid continuous movement
Drawn Forgeries Show:
- Low velocity (shaky, tremulous lines)
- Blunt starts and stops (pen resting before moving)
- Uniform, heavy pressure (the "death grip")
- Unnatural pauses or pen lifts at junctions
Analyzing Pen Lifts
Where a signer lifts their pen is highly habitual. If an exemplar shows continuous flow connecting the first and last name, but the questioned signature has a lift in the middle of a continuous letter, it is a massive red flag. This often happens because the forger needs to pause to look at their reference material.
Visualize Pressure Gradients
Upload a macro shot of an ink trace to our tool to mathematically map the pressure variations and detect uniform "drawn" pressure.
Launch Pressure ToolFrequently Asked Questions
Can a forger overcome kinematic tells?
It requires practicing a signature thousands of times until it becomes muscle memory, rather than tracing or copying. Even then, replicating the exact acceleration/deceleration profile of another human is nearly impossible for an expert analyst to miss.