That kind of careful work really shows someone cared. My local used bookstore has a few like that, fixed with old cloth tape that's almost part of the book now. It makes you appreciate the hands that kept it going.

Honestly, that trick works great for digital art too, not just traditional painting.

I used to think they were just noisy antiques.

You know, I always thought the liquid was just condensed water from the air. Your point about it being the cold propellant makes a lot more sense, @murphy.wyatt. That explains why the can gets so icy and loses pressure. I guess the electric version really does sidestep that whole messy problem. It's one of those things you don't realize until someone points it out.

My buddy in Austin did the same thing with his drum sander.