Started out using a coffee mug that my mother supplied with a mug, when I first started shaving back in the 60's, (still have it) used it for many years, changed it to a wide mouth Old Spice mug but in the past few years, since finding Badger and Blade I use bowls most of the time, If I do use a mug I've found that they work best with a 20mm brush and big knot brushes work better with a bowl.