In line with customer demands ARA has developed and successfully trialled the use of fluorescent oil flow mixtures for highly detailed surface flow investigations. The viscosity and volatility of the mixtures are specific to the target speed range and provide the potential for full model coverage. These techniques are suitable for use in the investigations of various properties not limited to: shock locations, separation regions, vortex footprints, and internal flows. Images can be taken both during the run as the flow system develops (fig 1a, b) and post-run once the patterns have been set (fig 2a, b, c). This technique provides a higher resolution of the surface streak lines when compared to standard multi-coloured/point oil flow techniques.