Stratified samples of artefacts from the Late Pleistocene deposit at the Klasies River main site, covering some 60,000 years, have been studied. Variability in the artefact sequence has been documented in the technologies of artefact production in addition to conventional typological analysis. Particular emphasis has been given to the recognition of the reduction sequences used in producing the pre-formed blanks that are a feature of the Middle Stone Age. The results show that the variability is due to changes between the dominant blade and or point technological conventions (traditions) through time. Technological study supports and gives meaning to the recognition of distinct sub-stages, MSA I (Klasies River), MSA II (Mossel Bay), Howiesons Poort and a post-Howiesons Poort at main site. These sub-stages are more than convenient, site-specific, organizational entities—they delineate separate technological conventions that may have relevance on a sub-continental scale.