With the introduction of high efficiency short acquisition time Raman microscopes at the beginning of the 1990's Raman mapping experiments became more realistic for many different materials. Previous to this time Raman maps of any useful size would take far too long for all but the strongest of Raman scatterers. A typical Raman spectrum used to take 30 minutes or more, a relatively small map of 50μ × 50μ using a step size of 1μ, would take over 50 days to acquire. Today the same map can be obtained in less than 4 hours. The use of an xyz mapping stage in conjunction with a Raman microscope is now common. The user defines an area on the sample that requires mapping and selects a step size and spectral acquisition time. Once the experiment is started the mapping stage drives the sample to the start position and takes the first spectrum, once this is completed the sample is moved by the requested step size and the next spectrum is measured.