And none have been returned, nor have any recipients advised me of postage due.

However, I only ship common chips, 3 at the most and stay under 2 oz. I affix 79 cents postage and mark the envelope "NON MACHINABLE" in red ink on the face, lower left side.

Lastly, and very importantly, I make sure the tacky cardboard is fully pressed together, making certain that it will easily slip through the 1/4" template slot used by the postal clerk to check thickness.

This also means that I crush the thickness, with the butt of my hand, where the chip(s) are located.

Again, I had had no issues, knock on wood.

Jim