I once received a paper carton with some plaques from France and the only thing that kept the lid of the box (kind of a shoe box; thin carton) secure was one wrapping of very thin cotton string -- the type of string use in a pastry shop; as if the contents were cakes or sweet rolls.

The string wasn't even knoted, but rather tied with a looped bow. No tape, whatsover... Couldn't believe what I saw when the postal clerk placed it on the counter... Everything inside was just fine, too...