The post office doesn't really take the time to care. They just slam our things through, so you need to take time to pack them carefully and include your shipping information in the package just in case it gets torn apart. I've seen some of the bad one, but most everything comes through fine. I wish I could afford the Tyvek envelops. I used to turn the priority and express ones inside out and use them, but the post office got smart to the deal and now they print on the inside, so that doesn't work. Sometimes, I've been know to put an item in a priority or express envelope and then put it in a regular envelope which will help withstand the abuse. You just have to make sure you wrap your books and fabrics in plastic to protect them.