i've been shipping quilts through our postal system for almost 10 years now- i guess i've been lucky- i've never had one damaged-missing or even late-
i always send them priority mail- with insurance and delivery confirmation.
my only question about using the vacuum bags is...can you actually fold the bag then to get into a box? my vacuum bags are stiff--stiff after i remove the air.
i use a kitchen plastic bag- make sure you put an index card inside the package with to and return addresses on it= a phone # wouldn't hurt either
it has been the most cost effecient way to go- i did try a couple other carriers (because of customer requests) they were alot more expensive- and we were not all that happy with them- so now i stick to the post office-