Re: Sewing machine corner
I use double sided tape a lot.
It takes the place of the pins my wife uses with her home sewing. I never use pins, they are very hard to use with even a few thicknesses of canvas.
I also use a stapler. A regular long reach office stapler. Will penetrate canvas and Dacron easily and the staples are easy to pull out with snips or small pliers.
Just because you're paranoid ...doesn't mean they're not after you!