Any time I get an old chip in a plain envelope my heart sinks. I've had more broken chips that way than I care to think about. Doesn't matter if it's in cardboard or wrapped in some kind of plastic. The machinery will snap them in two. I'm not familiar with the fee for non machine handling. You've heard the old saying about being penny wise and pound foolish. A bubble envelope is worth every penny. And even then you must take care the chips can't lay over the edge of each other.