Nance intended to demonstrate that certain small, bifacially chipped obsidian artifacts from the California Late horizon were used for cutting purposes, and were therefore not projectile points. However, both categories of edge abrasion noted by Nance, attrition and striation, may also appear on the edges of bifacially flaked artifacts during the process of manufacture. The purpose of abrading a biface edge is to strengthen the edge preparatory to pressure or percussion flaking. Criteria to distinguish edge abrasion during manufacture from abrasion deriving from use are presented.