is that if it's in a bubble mailer, it goes as a Parcel - period. 1 ounce parcel is $1.17 and 2 ounces is $1.34. If it's thinner (as in slot cards, but not chips) and goes as a first class letter in a regular envelope but it's stiff and can't bend as it goes thru their machine, you have to add 20 cents. I always check it out on the USPS website and write the postage on the envelope and make them verify that I'm right. As a general rule, I do OK. I was told that same thing about different postal clerks not agreeing on what the postage should be sometimes, but was also told that if there's a meter tape on it, they generally don't question it down the line. I will quite often put a meter tape on at work and so far haven't heard from anybody that I shorted them on postage.