if you have any thrift stores nearby, check every once in a while for a big nylon cutting board.


they use a similar material at work that you wouldn't need a bag for since weather isn't going to affect it. I've lucked into grabbing a few scrap pieces that work great for a rack. but if you probaly don't work where it would be available for you, I'm pretty sure it's the same thing they make cutting boards out off.