As a result of the classified caddis pupa chapter in the book, I have fielded several questions in regards to the construction of the dubbing brushes that I use to build that particular series of nymphs.  Well, to take out the guesswork I spun up this little video showing exactly how I make them.  Oh, and if you watch the video in it's entirety, you'll see an updated color of that simple scud I like to tie.  So grab a beverage, sit back and enjoy this one.