Marked: 2 1/2 single. Nothing on back. Found in manilla envelope marked the same.
Is this a paintbrush bristle sample or factory / salesman bristle sample? Brush for a photograph records? It's 3.75in width and flat.
Any guesses?
Looks like a wood graining brush. Wood graining is when an artist paints steel doors or other things to look like wood. My uncle does this and has a box full of brushes like that plus other tools setch as rollers and rubber stamps.