I learned this trick in reform school making parking signs for the warden. (Just kiddin’) Not sure if it has a name, but the idea is to make a painting mask by using the stencil punch out parts to mask the paint. For this application I needed three stencils of the same number. One is the gluing mask while the other two provide the parts to create the mask. Two sides of the vertical stab. The gluing mask prevents glue from going where you don’t want it. Remember that you are gluing the BACK of the stencil, not the front. Why number 2? I am building two FT Simple Scouts and I need to distinguish one from the other in the transmitter.