The present experiment examined the differentiation between hard stone, soft stone, and antler hammer in Upper Palaeolithic direct percussion, prismatic blade production through the experimental knapping by two knappers who were asked to produce a series of medium-sized blades. The use of two knappers in the experiment tested knapper variability in the resultant experimental assemblage. While the majority of the attributes of blades and proximal fragments – including the presence of lipping, platform preparation, bulb presence and prominence, and curvature amongst others – did not vary significantly in regards to which hammer type either knapper used, a number of blade attributes differed, significantly yet weakly, and there was almost no direct correlation between the individual knappers blades and the hammer type they used. This suggests strongly that for a given goal of producing medium-sized blades, this can be accomplished equally well using antler, hard stone, or soft stone hammers, and the resultant blades will be difficult to tell apart. Therefore, based on the results of this series of knapping experiments, we would be hesitant in using the 21 variables tested here to differentiate between blades produced with antler, hard stone, and soft stone hammer types in the archaeological record.