It just came in a solid cardboard custom fit envelope, slightly thicker to the smaller cardboard envelopes than most of my trades come in. They didn't do any extra protection. There might be some slight rubbing at the edges, but I find the individual envelopes that Bookdepository use usually provide better results than Amazon's big boxes.

But I've also ordered some big book (Marvel Omnibuses) from Amazon and they were shrinkwrapped and treated with some better care too.