I recently cut in several divided-light sashes with a 1 1/2" Lehigh and had excellent results, in fact the best I've ever had. I found it to be delicate enough (though it's billed as a rugged exterior brush) for very fine work. I was able to control the edge to the point where cleaning glass with a razor afterwards was a very short job, and in some places unnecessary. This brush has good spring and a very sharp, controllable edge -a pleasure to use!rnrnJim @ JCConstruction.