SWGMAT Guidelines
Definition
Guidelines issued by the Scientific Working Group for Materials Analysis (US), which define best practices for forensic ink analysis including method validation, reference database use, and conclusion reporting standards.
- Issuing body
- Scientific Working Group for Materials Analysis (US)
- Covers
- Forensic ink analysis
- Addresses
- Method validation, reference database use, reporting standards
Common questions
Why does ink analysis need its own guidelines separate from general document examination standards?+
Ink dating and comparison rely on chemical analytical techniques distinct from handwriting or paper examination, so SWGMAT's guidelines address the specific validation, chromatographic reference library, and interpretive concerns of ink chemistry that broader document examination standards do not cover.
How does reference database use factor into an ink analysis conclusion?+
Examiners compare an ink's chemical profile against a reference collection of dated ink formulations to estimate when it entered production or use, and SWGMAT guidance governs how that comparison and any resulting dating opinion should be validated and reported to avoid overstating precision.
Related terms
- ATR-FTIR (Attenuated Total Reflectance FTIR)
- An FTIR sampling mode in which infrared light undergoes total internal reflection in a crystal pressed against the sample surface, probing only...
- D Band and G Band (Raman)
- The characteristic Raman bands of graphitic carbon materials at approximately 1350 cm-1 (D, disorder) and 1590 cm-1 (G, graphitic C-C stretch); diagnostic...
- ENFSI FIDE-WG
- The European Network of Forensic Science Institutes Forensic Document Examination Working Group, which publishes best-practice manuals for document examination methods including ink...
- ESI-MS (Electrospray Ionisation Mass Spectrometry)
- An ionisation technique for LC-MS coupling that gently ionises analytes from solution at atmospheric pressure; produces molecular ion clusters and charge-state distributions...
- Photodiode-Array (PDA) Detector
- An HPLC detector that records a full UV-Vis absorption spectrum at every elution time point, producing a 3D data matrix (time, wavelength,...
- Reversed-Phase HPLC
- HPLC using a non-polar C18 stationary phase and a polar aqueous-organic mobile phase; components elute in order of increasing hydrophobicity; the standard...
- Rf Value (Retardation Factor)
- In TLC, the ratio of the distance migrated by a component to the distance migrated by the solvent front; a characteristic value...
- Solvent-Loss Dating
- An ink dating approach based on measuring the concentration of residual semi-volatile solvents (particularly phenoxyethanol in ballpoint ink) relative to a non-volatile...
- Video Spectral Comparator (VSC)
- A multispectral imaging instrument combining UV, visible, and near-infrared illumination with selectable emission filters and a calibrated digital camera; the primary bench...