[zcaveman]

I have been using different grades of cardboard boxes for the past eight years and do not see any degradation.

I also use plastic crates and have some stuff in plastic bags from Wal-mart. Not a problem.

Just no candles or other items that will melt under high temperatures.

The heat has affected some of the ornaments that use glue as a part of the ornament (halo, etc). We have repaired them and moved them to a shelf in the garage.

Before you store things in the attic, think - will these items be adverse to high heat.