Yes Archie... That's how I've been told to do it. No more than ¼" thick... and flat, no lumps.

We have a plastic template with a ¼" slot. I've been told that if mail piece will fit through the slot, and there are no lumps, it should be charged the "Letter" or "Large Envelope" rate.

Since I also mail chips, it was suggested that if I mail a single chip, place it between two thin pieces of cardboard so there is no lump, although I think the padded envelope, chip and cardboard would exceed ¼" in thickness.

A while back, I did a trade. The chip arrived in a regular #10 envelope with 39¢ postage. The chip was sandwiched between two pieces of corrugated cardboard, that adhered to itself and held the chip securely, without damage.

I sure would like to know where to get that cardboard!

Regarding confusion at the post offices, after the new "Forever" stamps went on sale, before May 14th, we received an email advising that they were 41¢. Apparently, some clerks were selling them for 39¢.