Current inspection and QA technology is dominated in the packaging industry by on-line beta gauges, capacitance testing and infrared technology as well as off-line microscopy and basis weight processes. The optics industry uses standard interferometers, gauge block comparators and other contact technology. Current Dual light source interferometer technology, employed by Lumetrics, allows rapid off-line and on-line non-contact inspection of multi-layer plastics and coating applications, as well as optics and optical assemblies. Practical applications in numerous industries will be discussed. Results of online testing of a multi-layer label stock will also be presented.