Paint

As with most types of "trace evidence" it is not generally possible to individualize paint evidence to a single source to the exclusion of all other sources.   The utilization of a proper analytical scheme; however, can make it possible to associate known and questioned samples to the exclusion of most other paint samples in our environment.

Paint consists of two parts: the "vehicle" which is composed of the organic polymer, additives and solvents and "pigment" which includes inorganic (non-color producing) extender pigments, organic coloring pigments and inorganic coloring pigments. 

Through the analysis and classification of paint binder (polymer and additives) systems we can generally determine the intended end use of the paint (automotive, architectural, industrial).  In cases involving automotive paint, we can often determine year, make and model of the vehicle from which the paint originated.   

Our state of the art analytical scheme for paint analysis includes micro-fourier transform infrared spectrometry and pyrolysis gas-chromatography mass-spectrometry for organic components of paint and polarized light microscopy, visible microspectrophotometry and scanning electron microscopy-energy dispersive spectroscopy for inorganic and color analysis.