The Help documents say  "Consider using an inner layer of plastic", I wish they would require it.

You can always send in feedback to the PBS Team for any suggestions you think should be implemented.  Not saying it will change anything, but it never hurts to try.  And if nothing else, you may get a response back from them explaining WHY they won't make it a requirement.

Personally, I am in the no plastic camp based on how I wrap my books.  But that is a discussion for a different thread and I'm not going to go into it here.

Edited to fix typos.  Now I remember why I should type with both hands...

For hardcover books, if I don't have bubble mailer at the time, I will mail them in a cereal box.  This protects the edges & corners from getting crushed.

I find that there are plenty of wrapping supplies readily at hand in my house. There seems to be a never ending supply of junk that finds its way into my mailbox. I always open my mail near my desk and cull out anything that may come in handy to wrap books.

From tyvek to sturdy larger envelopes to plastic liners that magazines come in. It is a book-wrapping bounty.

I never ever buy book wrapping material. Reusing material makes me feel creative and friendlier to Mama Earth.

I do buy packing tape, the dollar store usually has rolls available.

Almost any material can be used to wrap a book if you use enough tape. Leaving some of the package free of tape will help the receiver get to their book. But plenty of tape around the edges will help keep the evil USPS machines from tearing open packages of books.

Mass market paperbacks don't require any kind of special packaging.  Hardback books are typically damaged on the corners and on the edges of the spine.  The answer is to protect these areas.  This can be done easily by placing the book inside a stiff envelope like the free ones you can find at usps, fedex, ups, dhl, etc and wrap it tightly around the book.  After this, just cover the envelope up with whatever you want.  I just use the soft envelopes at fedex and turn them inside out.

Do not use the free priority mail envelopes!  If it is found to be in a USPS envelope, the full highest price will be charged to the receiver!

A manila folder works great.  Or a cereal box. 

I put my books inside the plastic wrapper my daily newspaper comes in.  The daily size is perfect for standard paperback and harcovers fit nicely in the Sunday bag.  Then I use the two sheets of paper that the PBS label prints out, wrap it like a birthday gift baox, and run tape once all around the page edges and spine.  Then clear packing tape goes all around the rest to keep the label area from blurring if the print gets wet.  No one's complained about anything I've sent getting damaged.

I've had a couple of books shipped in mailing envelopes get mangled but the books have still be readable fortunately.

One last thing to consider.  Make sure you tape over the address (both to and from) on the label you affix to the package.  That way if the package gets wet, the address won't run and end up being unreadable. 

Good suggestion from Kate H.  But always leave some un-taped area on the front of your package in case the PO needs to use an ink stamp.  The ink does'nt adhere well with packing tape.

-RD