I missed adding one more link that I found to be very useful since I am about ready to brush Shellac for my first time using this product. This video is presented by Brian Miller a professional finisher at Wm Ng Woodworks. I really enjoy the tips, jigs and instruction that come from Wm Ng, an engineer and woodworking instructor.
Brian Miller gives a great presentation on selecting and using brushes for finishing. This video not only shows what brushes to select, but how to use them as well as how to clean them. I highly recommend this video. I liked it, a lot.
Choosing and using Brushes for Finishing, Brian Miller at WmNgWoodworks. 20:51 min
-- --- Happy Howie