Last week I had the opportunity to run a workshop with the experimental archaeology group at the University of Chester (thanks Barry Taylor). The aim was for individuals to go from zero experience to producing a barb and tang arrowhead from a glass bottle. It went pretty well in that almost everyone (sorry Barry Taylor) came away with something approaching an arrowhead. Perhaps more usefully it introduced the participants to the joy of knapping, as well as the functions and effects of hard hammer, soft hammer, and pressure flaking. It brought home to me again, how difficult the thinning process is, and also, how difficult it is to teach. One thing that worked well was encouraging people to listen to the sound of their hits, and to identify the sound associated with the result they wanted. A second aspect that has occurred to me afterwards is perhaps to shift the focus onto producing the kind of flakes required. If someone understands how to consistently produce thinning flakes, then actually thinning a piece of glass should become easier. Easier perhaps than being focused upon the more complex goal of trying to make an arrowhead. I am running the same workshop in 2 weeks time at the University of Manchester with third year lithics students (thanks to Elizabeth Healey). I will test this idea to see if it helps a person to master the thinning process. Let’s see.