Looking to try a new rack design but I have hit a mental wall on what to use for shelves.

Rack itself is a 3 wall design

I want to find lightweight material that hopefully is vented, strong, will not rot and hopefully cheap.

Since this would be a lidless design I thought about the plastic "egg grate" material used in many incubators. Not sure if it is strong enough or smooth enough to avoid injury to the animal.

any ideas?