I am about to have a brush made for lathering in a very large scuttle. I figure I would need a larger brush, 28mm knot and perhaps a 54mm or a suggested 1:2 ratio of knot to loft. What I am unsure of is the shape. What are your opinions of the shape of this brush that would promote bowl-lathering, e. g., bulb, fan, hybrid? Thanks for your assistance.​