Just wanted to mention something I learned at the April 2021 Fiddle Hell Festival. 

Cello Workshop Instructors, as well as participants, were ALL raving about how great the "Stringvision Bowgrip" is! 

This is a very simple little frog covering - very sleek/nice looking.  The material keeps your fingers from slipping and there's a nice little dimple/divot for your thumb! 

@Fiddlerman -

I seem to remember you asking for suggestions to add items to the Fiddlershop, but can't find that thread.  

I don't own one, but after all the trouble I had finding a bow with a good resting spot for my thumb - I think my playing would have sounded MUCH better with a much more relaxed bow grip, EARLIER... if I'd just had one of these! 

This Bowgrip by Stringvision might be a great item to add to your inventory. 

This is elegant and stretchy, so fits over all Cello, Viola & Violin bows! 

- Emily