I haven't read all the replies yet so somebody may have suggest this already.

I grab a handful of the cardboard coffee cup holders at the coffee shop and use them. I put the chip in an old flip, but not necessary and then inside the cardboard coffee holder. Then I tape the edges and put into a small white envelope. I only do this with chips of no value, but haven't lost one yet.

Now the tricky part. There is one postal clerk at my PO who can ring it up and a white postal sticker comes out of the machine that gets put on the envelope. The other clerk has no clue how she does that so he puts on 64 cents in stamps and hand cancels it.

Good Luck
Barry