I found a pack of shrinky dinks in a drawer a few weeks ago and I thought about making some charms. I have an old one a friend did for me with colored pencils, and while it came out wonderfully I've been seeing people somehow getting a much smoother look than what can be achieved by colored pencils. I read that you can use acrylic paint on shrinky dinks if you water it down a little bit. Does anyone have any experience with the process that could give me any tips or warnings on what not to do?

I'm also interested in making stickers to sell, but a huge issue I have is durability. You see, I'm of the mindset that if I'm gonna do something, I'm gonna do it right. I want something that's durable enough to use as bumper stickers. The printer I have access to is an Epson which has waterproof ink, but I'm looking for paper suggestions. I'm looking for bumper sticker paper or printable vinyl or something. I want these stickers to be as weatherproof as I can get them without having to get them professionally done.