Can anyone tell me why some paleo's points edges were ground smooth? Thanks

grinding: A method of stone working employed in the smoothing of an edge or surface by rubbing it with a hammerstone or other abrader prior to use. Performed on projectiles or blades so that hafting materials (lashings) would not be cut by sharp edges of the base. Also commonly referred to as Basal Grinding when the base and sides of the stem have been ground. There are varying degrees of grinding, typically referred to as light, moderate or heavy.

ic. makes sense. but why did they stop gringing? did they create new ways of putting the point on the shaft without using lashings? thanks

I have actually seen points found in coastal areas that had a natural form of asphalt mixure attaching them to the shaft/haft; but other than that I don't know.

ic. thanks brad.