In addition to this discussion, once I cut my aluminum roof flashing into small strips, I put a bunch of pieces together and use vice grips to hold them together then drill the holes all at once. It saves a lot of time. I also trim all the corners to be more rounded like a text bubble, then etch each side with an engraver. A dremel with a diamond tip works too.
This is a great idea! I’ll be using it this year. They make paint pens in different colors (my boss gets black, white and yellow). Those would surely last at least a season.