i see that i can just print it on regular printer paper. i'll just do that ,then apply to box/envelope and cover in packing tape so it's waterproof.
i figure padded envelopes for overs of 5 or less (each unit in it's own anti-static bag and bubble wrapped) and for bigger orders, boxes with foam inserts to separate the units. i already have a ton of cardboard and foam from other stuff, so it's no big to do that.
You can do that, but they don't want you to tape over the barcodes, and they're a bit of a pain to avoid (I've done it hundreds of times).
Please, please don't use a padded envelope for my shipment. Use a box with packing material (crumpled newspaper works) surrounding the items. Understand that the mail gets beat the f up. You should see what some things look like after they've been through it. I can imagine anything in a padded envelope getting thoroughly crushed.
I use boxes like these:
http://www.ebay.com/itm/200-6-x-3-x-2-White-Corrugated-Shipping-Mailer-Packing-Box-Boxes-/380554330622