Tank lid coverings?

[doomsong]

In the past I used plastic wrap on the lid to help keep humidity in. That was before I got my 3rd cat whose obsession is plastic. Any advice for using something besides plastic wrap? What does everyone else use?

[curlysister]

My 40 gallon had a thick plexi glass lid - it was strong enough that the cats (well not the big chonky one, but the others) could sleep on it. My current 65 gallon tank has a home-made thin plastic-y thing. So I put an old wooden shelf on top of that to hold the cats.