I agree that you should never put on the outside of the box that there is something of value inside, like a quilt. It's a signal to thieves to help themselves, and in this economy, sorry to say, more things are disappearing not just from the mail, but from bags at the airport, hotel rooms, and public places. As the economy worsens, this will only get worse. Also, attach to the quilt both your name and address, and the name and address you are sending it to, and I mean attach. Don't just toss a paper in the bag. Pin it to the quilt in a couple of places. Also sew your name, date of quilt, whatever identifying information you usually put on a quilt -- and sew it into the quilt in such a way that it would damage the quilt to remove it. Sorry, I guess I spent too much time in the big city. But that will make people think twice, especially if the plan was to re-sell it.
I use a UPS box as my mailing address, so I am good friends with the people at UPS. I am always trying to make sure I know how to get things safely where I need them to go. They tell me that the number one way to ensure that something gets to its destination is to take it to the UPS store, and let them pack and label it. When them pack it, they are invested in making sure it is done correctly, and will arrive in one piece (I've sent many delicate items, and they've all arrived in pristine condition this way.) They are also invested in just plain seeing that they arrive, since they were responsible for doing the shipping labels. And of course, insure it, for the proper value. I have been told that the loss rate on packages packed by UPS personnel is less than 1/4 of 1%, and if they packed it, there is no quarrel over paying the full amount of the insurance. Of course, insist on a tracking number, and then, for heaven's sake, track it! If it's starting in Las Vegas, and headed for New York, and somehow ends up in Portland, Oregon, you'll see that on the tracking. That's when you get on the phone and find out what the heck is going on. Don't wait until it's lost! Personally, I've never had that problem, but apparently it does happen on occasion. Something gets put on the wrong truck, etc. So stay on top of it until it arrives. Quilts are just too important; they have too much time, money and heart invested in them to do less. Personally, I've sent lots of things this way, especially sensitive materials for my husband's business, when it had to be somewhere by a certain date or it was a disaster, and I've never had a problem when I've let them pack it. Cost's a little more, yes, but worth the peace of mind, at least to me.