Historical Product Inventions

Historical Product Inventions

During my initial apprenticeship period, I had the good fortune to train with document examiners at the US Postal Inspection Service in San Bruno, California. A document examiner in the laboratory presented a copy of a postcard to me, postmarked in 1912. She asked if...
Instrumentation

Instrumentation

A properly equipped laboratory will have a a variety of instruments to use during examinations. One that is particularly useful, is the Video Spectral Comparator (VSC), that allows an examiner to compare inks. The VSC relies mainly upon the use of the infrared light...