[Dx-qsl] US Buro Mgrs: How many QSLs to exceed 1/4 inch thickness?

[Tim Goeppinger]

I have a question for U.S. buro mgrs and sorters:

The US Postal Service has changed the rules in the last couple of years regarding the
thickness of letters.   Anything over 1/4 inch thick and rigid, and the item is considered
as a package, and is sent at a higher rate.  Because of this, my envelope with 50 cards
in it arrived today with 62 cents postage due.

Is there a rule of thumb that I can politely tell my sorter what is the maximum number
of cards he can send, and still be considered a "letter"?  I realize the thickness of
QSLs can vary, but I am just looking for a rough estimate.  Maybe I should be asking for the number of ounces?  Mine was about 6 ounces.

Tim K6GEP