We've not used the Eagle Creek folding envelope (not sure why; as many Eagle Creek goodies as we have, we should have stock in the company), but I once read to use the 2 gallon zip lock bags. We did on our latest trip to CA and they were grand. Once you put the clothes in them, just roll the bag up prior to zipping shut the last inch or so, it squishes out the air and you're ready to go. I also thought (could be an error in judgement), that if anyone went through our bags, everything would be clearly visible.

They won't have the life span of the Eagle Creek envelope, though.

Cheers all,

Peggy