Okay, it should have been obvious, but it wasn't, and I'm passing it along so others won't suffer. I recently signed at an outdoor event in Florida. I took along a box containing a dozen books and a bunch of items I would need to set up a table and decorate it attractively. Here's what I found out.
One book got ink along the outside edges from rolling up against a pen.
One book got tape residue on the cover from being stuffed hurriedly into the box when it started to rain.
One book's outer cover got punctured from something sharp, probably during above rush to beat the rain.
Several books got wavy edges from exposure to the humidity.
Result: some books that aren't sellable. Considering the fact that we don't make a lot of money on this whole writing thing anyway, it's doubly disappointing when a book is spoiled.
Recommendations: 1) Wrap books in plastic padding, seal them in a trash bag, and then set them in their own box. 2) Only get out one or two books at a time if the weather is muggy. 3) Avoid rain.
If people are going to pay for a hardcover, they'll expect it to be in perfect condition. Thinking ahead is a good thing.