cork

Somewhere I ran across the idea of using cork for a backdrop. Looking
around on the web, I've found cork bark and cork wall tiles.

The cork bark is way too thick - usually 1"-2". I don't want to take
that much out of a 12" deep aquarium. The wall tiles are mostly 3/8"
which would be about right.

But I don't know if the tiles are safe, since most of them are made from
granulated cork in a binder.

If anyone on the group has used them with good results, could you let me
know what kind and where you bought them (if online or mail order).

Thanks.

BTW, I plan on making "rock" walls from clay that will go about halfway
up with cork the rest of the way. And maybe cork only on the sides.