Introduction
When I lived on the Wirral in the 1980s, I was lucky enough to live close to an art shop called Tapley's run by the very knowledgeable Irene Brown. One day I was chatting to her and mentioned that, no matter how careful I was, my brushes didn't last very long; be they sable or synthetic. She reached under the counter and produced a small box of "special" brushes from Isabey of France. This was my introduction to the wonders of Kolinsky sable brushes: I've never looked back.
Current situation
Decades later I've still using Isabey brushes, but my main source of Kolinsky sable brushes has shifted to Rosemary's Brushes.