Erasure (Mechanical)
Definition
Physical removal of writing by rubber, knife, scalpel blade, sandpaper or eraser. Disturbs paper fibres, thins the paper, and lifts the sizing and surface gloss.
- Tools
- Rubber, knife, scalpel, sandpaper, eraser
- Effect
- Fibre disturbance, paper thinning, gloss loss
- Detection
- Oblique lighting, low-power microscopy
Common questions
How is mechanical erasure identified under examination even after new writing is added over it?+
Oblique lighting and low-power microscopy reveal the roughened, thinned texture and disturbed fibre pattern left in the paper surface, which differs visibly from the smooth, undisturbed area around it.
Can mechanical erasure be distinguished from ordinary paper wear or handling damage?+
Yes. Erasure produces a localised, sharply bounded area of fibre disruption tied to the removed writing, whereas general handling wear tends to be diffuse and unrelated to any specific text location.
Related terms
- Addition (Interlineation, Insertion)
- Fresh writing squeezed between lines, in margins, after the last entry, or in blank spaces left in the original document. Often shows...
- Alteration
- Any change made to a document after its original execution, including erasure, obliteration, addition, substitution and overwriting. A material alteration changes the...
- Erasure (Chemical)
- Removal of ink by bleaching or oxidising agents such as sodium hypochlorite, chloramine T, oxalic acid, potassium permanganate or hydrogen peroxide. Leaves...
- ESDA
- Electrostatic Detection Apparatus; detects latent indentations in paper by charging the surface and cascading toner particles, revealing tracing stylus pressure and writing...
- IR Luminescence
- Emission of near-infrared radiation by ink dye molecules when excited by visible light; different ink formulations luminesce at different intensities, allowing differentiation...
- Obliteration
- Covering of existing writing with an opaque layer (ink, correction fluid, or correction tape) so that the underlying text is invisible in...
- Overwriting
- Tracing over an original stroke with a fresh stroke, usually to change a digit or letter. Detected by stroke thickness, hesitation, and...
- VSC-8000
- Video Spectral Comparator by Foster + Freeman, the standard QD instrument in CFSL and GEQD labs, with broadband visible, UV (254, 365...