Forensic Laboratory

Forensic laboratory
The Forensic Laboratory at the National Postal Museum

The National Postal Museum (NPM) houses a laboratory with a unique combination of equipment for the analytical or forensic study of philatelic materials. Analytical philately is the study of the materials that make up the objects (papers, inks, pigments, gums, etc.) through the use of scientific and engineering tools, such as elemental and molecular analysis, microscopy and different light wavelengths, or through mathematical and statistical study. Such techniques go beyond what the human senses can register and allow characteristics and components of philatelic materials to be found, identified and examined. Such characteristics and components include a wide range of things from watermarks to plate flaws, and from color differences to the molecular breakdown of paper.


The NPM lab holds a VSC800/HS, which offers non-destructive examination and imaging of philatelic materials.

Foster and Freeman VSC8000/HS with a Leica M205C Microscope (magnification up to 1280x)

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Researcher working with the Foster and Freeman VSC6000
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Leica M205C Microscope (magnification range from 78x to 1600x)

The Video Spectral Comparator (VSC) uses a variety of light sources and filters to image materials in the ultraviolet, visible and infrared wavelength ranges. In combination with a high-resolution color camera, researchers can examine, compare and photograph minute details on a variety of materials. Researchers can measure objects, pinpoint particular spots for study, locate flaws and alterations, study watermarks and other security devices, and overlay images for comparison. This instrument is frequently used for the study of color, which is defined by how light interacts with material. Materials reflect and absorb light at a particular wavelengths depending on the optical properties of that material. The VSC also includes a spectrometer, capable of creating and storing spectra (visual representations of energy/wavelengths of radiation or particles emitted by a substance), and providing color values and chromaticity (color) charts.

 

This page will be updated further in the autumn of 2021.


Researchers and scholars writing in the fields of philately and postal history are welcome to use the laboratory for the study of philatelic materials. NPM staff will provide basic training and oversight on the machines but will not analyze research results. To make an appointment to use the laboratory, please contact the Blount Research Chair at: NPMResearchChair@si.edu.