Paint

 

 

 

Color comparison of two red paint layers, showing they are different shades of red

 

 

Color comparison of two similar green paint layers.

 

Paint examinations usually arise from cases involving hit and runs, destruction of property, and burglary. Automotive paint can vary by manufacturer or assembly line and can change from one year to the next. Questioned paint from a tool or a transfer on an automobile can be compared to a known automobile paint standard to determine if a possible common origin exists.

 

Paint may have many layers, so care needs to be taken to ensure all layers down to the substrate are collected as standards for comparison. Paint standards should be collected near the damaged area. For automobiles, standards should be collected from all vehicles involved as well as suspected paint transfers.

 

Paint analyses may include microscopy, microspectrophotometry (MSP), Fourier transform infrared spectrometry (FTIR), and scanning electron microscopy with energy dispersive spectrometry (SEM/EDS).

 

Cross sectional view of a paint chip showing four layers, a thin white, a thick white, a color layer and a clear top coat layer.