Kenneth J. Stout was an important figure in the development of surface metrology, and in particular of roughness measurement and characterisation, during the last decades of the twentieth century. He made substantial contributions to the statistical characterisation of rough surfaces and the application of this work to tribological measurements. Later he was instrumental in developing and popularising practical techniques for three-dimensional description of surface roughness, including the well known "Birmingham 14" set of roughness parameters. Finally he was one of the first to promote the application of wavelet transforms to surface metrology. This memorial discusses his personal contribution to the subject and attempts to set it in the context of historical developments in the field. It includes what is hoped to be a definitive bibliography of his journal publications and those of his co-workers.