So far, I have never found brush hairs in any of my prints. But, the first thing I did to the brush was a bead of super glue to the area where the bristles meet the handle. No more hair, except those falling from my slowing growing baldspot.
My other concern is the Richeson brush has metal in the handle & I am not sure thats a good idea with kallitypes. Some people have said avoid metal in the brushes at all cost, so it gives me a reason to pause.