Achieve precision flatness to Ra in many materials with GMT Flat Lapping Machines.  These attractive and self-contained units use sodium lamps to produce a brilliant glare-free light of known wavelength. You can observe contrasting light and dark bands on most reflective or semi-reflective surfaces.  In order to obtain the highest reflectivity from a lapped surface for light band interpretation, it is generally required to hand polish sample parts briefly after work has been lapped. GMT polishing stands effectively handle a fine grade polishing paper,  holding it tight to prevent rounding the edges of the work, yet permitting easy access to a new section of paper when desired.