Last night I was talking to a prospective customer and the subject of knob material came up. He expressed a preference for a knob where the profile is a convex curve. The reason for this preference is that if the fly line became wound around the knob, it would not be able to slip off a concave knob (particularly so when the wrap overlaps itself; it becomes “locked”). I have created many strange tangles while fishing, but this one had not yet come up. It probably will now, since I know about it.
So I made the knob this morning. Had to make a new pan for the base of the knob, since my standard pan was too small.
Does anyone have other insights on knob shape?