:I've had my chondros in melamine cages for over 4 years with no problems. I kept jungles in these same cages for the 4 years prior to that. Like Heather said, just make sure all joints and cuts are sealed.
::For GTPs (and ETBs) I'd recommend a cage made of high impact, light weight plastic such as are available from Vision, Boaphile cages, etc.
::i use habitat systems brand enclosures myself.-darren