I use them all the time for mailing quilts out and I get them in those boxes. You can go to the Post Office's website and do a calculation on the cost of shipping in different boxes or envelopes. I use my kitchen scales to weight small items. I can get a full size quilt, batting and backing (all quilted) in a medium sized priority box -- for $10.70. :)

The last quilt I sent out was 87x87. I checked the FedEx site, the UPS site and the PO site....the Post Office was the cheapest....even AFTER I added insurance and delivery confirmation.

On edit --- I forgot - FedEx WON'T come by my house (in the country) to pick up...only deliver.

When items weigh more than 11 oz. the first class postage becomes Priority automatically. At that weight you have a choice of Priority or Parcel Post. Either of these options incurs a different cost for each different delivery zone. So a regular Priority package from New York to California crosses about 5-6 zones and is more expensive than a Priority package to a nearby zone. Using the flat rate Priority products not only saves you money when the item is heavy, it eliminates the extra zone charge. It enables mailers to always know how much their postage charge will be without having to use a zone chart. It also allows the Post Office to know that the postage is correct without having to weigh each item and check the from and to zip codes.
By the way, FedEx is cheap only for organizations who have a contract and account with them. If you don't work for someone with a discount and you send FedEx, you will pay consideably more. At least the Post Office charges pretty much the same for packages to anyone who shows up to mail!

How do you squish a full size quilt down enough to get it into a medium size box? I just mailed out one and there is no way I could have gotten it in a medium size priorit box. I barely got it in the box I did.

The cost of shipping has gone through the roof. I mailed out 4 boxes last week and it cost me $145. I bought the boxes at the PO. Bought them. They would not mail one because the lady said it was too heavy. Okay it was their box I bought. I went to UPS and they weighed it (32 lbs)& said the PO should have taken it. I went with UPS to avoid the PO hassle again. So I am going to be selective as to what I mail out or how much, if using the PO again. If they do not want the business, I will take it UPS which is closer to my home. This topic has been enlightening. Thank You for starting it. :thumbup: