I'm new to DE shaving and am using what was my grandfathers shaving brush. I think it would be fun to get into forming my own brushes and have seen various threads regarding how to secure the knot, how to deal with hollow handles, wood types, and just about everything except how deep a knot should be within a handle. So, what is a good depth for a knot? Does a face lather require the knot to sit deeper into the handle?