People who have sent me chips in "that sticky stuff" have all arrived just fine. They also had the chips in an Airtite or similar device.

I have put chips between two pieces of light cardboard, stapled closed and used business envelopes or clasp or mini jets packs, or bubble packs, without a chip loss yet. The cardboard is the full size of the inside of the envelope.

The part that I think helps get my chips through safely is that they are sandwiched between cardboard (I like that sticky stuff even better, but I'm too cheap to buy it) so they can't flop around, get slammed, or fly out the end of the envelope. It's one big unit. (Did Mae West say that?)

The point of this is anchoring the chip, within the envelope, which keeps it safe.

I've had people mail me chips, loose in an envelope, so there might be some dumb luck involved as well.