question re: books in M bags

I was at post office last week and the lady gave me 2 huge duffle type bags for my books. She said they needed to be pakced loose - i.e. not in a box which is then placed in the bag.

How do you keep paperbacks and other things from gettings all bent and  messed up? I was thinking of wrapping each one like a gift but was curious how others managed it. Some of them are books say 8.5 x 11, yet still paperback. Others are normal "pocket sized" novels.

Or maybe I'm the only cheapie who buys paperback.

I buy paperback!

Might I suggest using rubber bands to keep the books closed?  Two around each book, in a "+" type pattern would probably do the trick.   

You can use twine and tie the books together in groups of 4 or 5. 

I've sent about 10 M-Bags and only had a couple of things knocked around.  But I have had several items get WET, which really annoyed me.  I was just in the States and sent my next-to-last load, which includes my Riverside Shakespeare.  I'm a little worried about it.

oo didn't think about the wet possibility. Maybe I should cling film everything tightly rather than a simple gift wrapping. If they open it to inspect, I'll just look like the biggest weirdo ever.

I'll be right there next to you looking like a weirdo!  I planned on cling wrapping my books as well!