Jerry,
I put the chip in a 2X2 cardboard flip. I use a manila envelope and scotch tape the flip inside the envelope so it doesn't move around.I put my stamps on it after weighing it om my small digital scale and mail it in my mail box. I avoid postal clerks. You can mark it non machinable, but I don't. Never had any problems.
Hope This Helps
Rick
P.S. Others advice may work also.