If using a Priority Flat-Rate Box or envelope for shipping, it's a no-brainer........it is what it is (flat rate). I have found descrepancies in charge rates when shipping something in a Kraft Envelope and/or Bubble-lined Kraft Envelope. It not only depends on the weight, the "thickness" of the envelope also determines which rate the Post Office person is to charge. Some PO employees could care less what the thickness is and charge the "normal" First Class Big Envelope rate (whatever that is??), while other post office personnel will test the envelope to see if it will fit thru a pre-determined slot size (they have a template to use). If it will not fit thru the slot, the envelope gets bumped up to "Package Status" (hence, a higher rate)........is how I understand it. Again, it may depend on who handles the package initially as to what charges apply.
Hope this helps............
Moto-Kafe screwed with this post 12-01-2012 at 04:08 PM