Not sure I can help but just as a warning, if you were to mail me a chip in a standard envelope my local post office will charge me postage due on package rates. They consider anything other than paper in an envelope as a package, just like cardboard photo mailers, bubblepack mailers, etc. If I try to mail chips in a standard envelope they won't even accept them or they will try to charge me package rates even if it's in a regular envelope.

Some post offices accept things they technically shouldn't while others are more strict. I get similar packages with slot cards, etc. but they wind up costing me extra money when the sender sends things incorrectly. The trouble arises when your post office accepts the item at one rate and the receiver's post office thinks it should be another rate, then the person getting the item may be charged postage due.