Carbon-Film Ribbon
Definition
A single-strike typewriter ribbon with a carbon coating that transfers completely to paper on impact, enabling high-quality impressions; the used ribbon retains a legible mirror image of the typed text, recoverable from the cassette.
- Type
- Single-strike typewriter ribbon
- Transfer
- Complete carbon coating transfer on impact
- Evidentiary value
- Retains mirror image of typed text
- Recovery point
- Ribbon cassette
Common questions
Why is a carbon-film ribbon more forensically valuable than a fabric ribbon?+
Because the carbon coating transfers completely at each strike and is not reused, the ribbon retains a legible, sequential mirror image of every character typed. A fabric ribbon is reused many times and only leaves a smeared, overlapping impression.
How is text recovered from a used carbon-film ribbon?+
Examiners advance and photograph or scan the ribbon under magnification, reading the mirrored impressions in sequence, sometimes reconstructing entire documents typed on that ribbon before it was discarded or replaced.
Does the presence of a used carbon-film ribbon confirm which document was typed on that machine?+
It provides strong supporting evidence when the recovered text matches a questioned document, but examiners also compare it with the physical typeface and mechanical characteristics of the machine itself to strengthen the association.
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- Pitch
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- SWGDOC
- The Scientific Working Group for Forensic Document Examination (US), which publishes standards for typewriter examination, handwriting comparison, ink analysis, and related forensic...
- Typebar
- A pivoting lever carrying a metal type slug that strikes the ribbon and paper when a key is depressed on a mechanical...