Carbon Black
Definition
A colloidal carbon pigment produced by incomplete combustion; the primary colourant in permanent black gel inks, Indian inks, and archival drawing inks; non-soluble, Raman-active, and analysed by Raman microscopy rather than dye-targeted chromatography.
- Origin
- Colloidal carbon from incomplete combustion
- Found in
- Permanent black gel, Indian, and archival drawing inks
- Solubility
- Non-soluble pigment
- Analysis method
- Raman microscopy, not dye-targeted chromatography
Common questions
Why can't carbon black ink be analysed with the chromatography methods used for other inks?+
Chromatographic methods such as TLC separate soluble dye components, but carbon black is an insoluble particulate pigment that will not migrate through a chromatographic medium, so it requires a technique like Raman microscopy that probes molecular structure directly.
How does Raman microscopy identify carbon black in a questioned document?+
Carbon black produces a distinctive, strong Raman signal from its graphitic carbon structure, letting an examiner confirm its presence and distinguish it from dye-based black inks that lack this signature, without needing to extract or dissolve the sample.
Why does distinguishing carbon black from dye-based black ink matter in casework?+
The two pigment types come from different formulations and manufacturers, so confirming which is present can help determine whether entries on a document were made with the same pen or ink batch, supporting or refuting claims about when text was added.
Related terms
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- The Bundeskriminalamt (German Federal Criminal Police Office) reference database of European pen ink formulations, used as the evidentiary baseline for questioned-document cases...
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- Iron-Gall Ink
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- Triarylmethane Dye
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- USSS International Ink Library
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