This is my first post - I hope it's in the right place!
My dad gave me this M. Grumbacher 3634 brush that was with his house-painting brushes...but I have a feeling it's more of an art brush. It's 3 inches wide and stamped "M. Grumbacher N.Y. 3634". I think it might be ox hair? The bristles are very dense and quite stiff.
I did some online research and it seems like it would be good for priming a canvas with gesso. But I was curious if anyone has seen this particular brush, or knows what this type of brush is called, what kind of hair it is, any tips for me on how to put it to good use.