The only way to make "sure" that damage won't occur is to go to the post office, make sure they put a meter strip on it, pay the extra $.20 for making it nonmachinable and then pray. I mail one chip in regular envelopes this way but in addition to the flip I wrap the chip in shipping foam. I figure what is the difference if a chip is put into a bubble warp mailer or is protected by foam and put into a regular envelope. BTW - I also put tape on the envelope to make sure that the chip doesn't fall out. Those lick-em envelopes just don't work very well without help.