In my first guide, I told you how to get free boxes and envelopes from the USPS.  Two more things you should know.  The USPS people are so stupid and incompetent that for about 2 years now, their online shopping cart for these supplies DOES NOT WORK.  You can call them on an 800 # and get these supplies, you want to write down their stock numbers first.  Second point, I got one of the flat rate Priority Mail Tyvek envelopes and tried fitting TWO of their free box, O-1096S, into it.  These fit just fine, no problems sealing the envelope, you can send up to 2 lb.s safely for $4.10 to any USA address.  Also note that next year the USPS will be selling first class postage which they promise will be honored, per oz., forever.  Check if this scheme will work for Priority Mail!