It is 7/8 full hollow. It makes this sound on the first half of the stroke as hand accelerates along the strop and which disappears by the time I slow down at the other end. Basically I hear white nose "wsh-h" along the whole way, and l slight "zing" along first half way. It also sounds about the same on the canvas, with general noise being more low-pitch and "zing" being little bit more pronounced because of that.