At the time 37:00 I had an epiphany,- the Law of Diminishing Returns applied here. Instead of outlining your shape with tape, carefully cut it out of a thick glossy paper (e.g., bristleboard) or plastic. Now fasten the outlined shape using hot glue applied close to the perimeter of your shape. When you press it down on the surface, you want glue to bleed out everywhere along the inner perimeter. Let cool. Remove the bled out glue with a knife. Now fill the shape with paint using whatever tools you are accustomed to. Let dry. Cut around the perimeter of the mask, and peel it off. Reserve the cut out shape for later masking when you are painting around it.
