For the last 20 years or so, I've been hipped to using this lightly coated thin aircraft cabling. And now, Trick makes it available commercially, so you could buy it at places like Sam Ash and Guitar Center. If you're tying knots with it, you do have to use a couple of pairs of pliers to grab it so you can pull it tight enough. But my P-85 strainers and butt ends have brackets that screw the cabling down so I've never had to tie a knot. But I have seen guys who have, and once it's set it last forever.
I used to stick with the snare cord, but that broke over time and usage, and then in one emergency I used shoe laces, which lasted a little longer. And years ago I went to Pro Drum in Hollywood lamenting about these stupid snare cords and that's when they set my snare up with the aircraft cabling. Best move ever!