For the Scenario B ReadyPost you can use any of the ReadyPost mailers... bubble, padded, box, etc. For Scenario A, which they do call "Regular Box Shop", the Guidelines repeatedly refer to using a "box"... not any other kind of packaging.
I've never even thought about using something else, because I have so many perfectly-sized boxes to re-use stacked up in my house anyway!
But since they use the term "box" exclusively and repeatedly for the Scenario A "Regular Box Shop"... just to be safe, I'd use a box.
Happiness is merely life's way of keeping you off-balance.
I think this was answered here in the forum by a representative from Bare. You can you use box, envelope, and bubble mailers as long as the weight criteria are met and it can hold the package securely.
Email Jeff Rose and ask. He usually always responds quickly.
Edited 1 time(s). Last edit at 01/03/2014 04:46PM by SecretAgentMom.