I just mailed a chip today in a bubble mailer via the postal machine. It was less than 3/4" thick (one chip) and it is flexable bubble mailer 001. Didn't stamp anything on outside...Used large envelope because it met the definition and machine said .88 cents like you posted. If they return it to me, I will head to the post office and request to talk to the Post Master...time will tell..no wonder the USPS is broke!