Precision Tool Technologies, Inc.’s Truform 2.0 and 2.5 Tracer Standards are designed to enable optical labs to cut edged lenses correctly the first time. The system is based on the fact that lens circumference is measured on the outermost point on the lens and that the lens locates on the bevel in the frame and the bevel of the lens, the C measurement. Also, frame calibration tracers trace using the end of the stylus against a straight wall. Different frame tracers have different tip geometries, which means that each frame can have a different size when measured in different manufacturers’ frame tracers. Lens size and frame fit are important because the C measurement on the lens isn’t where the lens locates in the frame, and the stylus tip in the frame tracer when calibrated is not the surface where the tracer stylus tip contacts the frame bevel when sizing the frame.