squirrel brush

I've been reading comments about brushes of different hairs, and am curious about squirrel hair brushes. I got one recently, Isabey # 7 quill mop. I did a small rough work for a next painting to test this brush. True to what I've read...the brush is dream to work with, and it carries color well, much better then I thought. I'll be careful with loading it when painting, or the painting will look like this one...a bit too strong to my taste.