It has long been accepted that the texture of a froth is generally a good qualitative indicator as to the performance of the flotation process. During investigation into quantifying froth textures by image analysis, it was observed that the grey level of a coal froth can provide significant information. The grey level showed correlations with flotation performance (e.g. ash content and froth mass flows rates) for both a single flotation cell and a bank of four pilot-scale cells. However, the two systems showed distinct differences in the texture of the froth surfaces. Testwork demonstrated that the effect of varying background illumination had a negligible effect on the results.