ENFSI EPG Protocol
Definition
European Network of Forensic Science Institutes Expert Working Group on Paint protocol; the European standard for paint comparison examination sequence and reporting.
- Full name
- ENFSI Expert Working Group on Paint protocol
- Governing body
- European Network of Forensic Science Institutes
- Scope
- Paint comparison examination sequence and reporting
- Applies to
- Cross-section, layer, and instrumental paint analysis
Common questions
What does 'examination sequence' mean in this protocol?+
It specifies the order in which tests should be run, typically starting with non-destructive layer and colour examination before moving to destructive techniques like FTIR or Py-GC-MS, so that irreplaceable trace material is not consumed before less-destructive comparisons are complete.
Why does paint comparison need a standard protocol at all?+
Paint evidence value depends heavily on matching layer sequence and chemistry correctly; without a shared examination order and reporting format, results from different laboratories become difficult to compare in cross-border cases.
Related terms
- ASTM E2937
- ASTM International standard guide for identification of paint binders by pyrolysis-GC-MS; specifies pyrolysis conditions, GC column, oven program, and diagnostic ion reporting.
- ATR (Attenuated Total Reflectance)
- An FTIR sampling mode in which the sample is pressed against a diamond or ZnSe crystal and the evanescent wave probes the...
- Backscattered Electron (BSE) Imaging
- An SEM imaging mode sensitive to atomic number and crystallographic texture; can reveal grain-boundary elongation patterns in the sub-surface cold-worked zone after...
- FTIR Microspectroscopy
- Fourier-transform infrared spectroscopy collected from a microscope-focused spot of 10-20 µm diameter; the primary technique for paint binder characterisation.
- IRUG Database
- Infrared and Raman Users Group spectral database; covers historic pigments, artists' materials, and museum-object coatings. Primary reference for art-investigation paint analysis.
- Likelihood Ratio Reporting
- A Bayesian framework for reporting paint-comparison conclusions, expressing the probability of the observed data given the hypothesis of common source versus the...
- Microtome Cross-Section
- A thin section of a paint chip cut perpendicular to the layer planes, allowing each layer to be examined separately by microscopy...
- Py-GC-MS
- Pyrolysis gas chromatography mass spectrometry. Thermal decomposition of a paint sample, separation of fragments, mass spectral identification. Definitive identification of polymer binders.
- Pyrogram
- The gas chromatographic trace of volatile fragments produced by pyrolysis of a polymer; acts as the polymer-class fingerprint in Py-GC-MS.
- Raman Microspectroscopy
- A vibrational spectroscopy technique using a focused laser beam to excite molecular vibrations in an ink sample. Non-destructive. Primary method for toner...
- SEM-EDS
- Scanning electron microscopy with energy-dispersive X-ray spectroscopy; provides elemental composition of each paint layer at 1-5 µm spatial resolution.