The Seven-cent Prexie
Third class with minimum insurance use
From January 1, 1949 until January 1, 1957 the cost of the first two ounces of third class mail was two cents and the minimum insurance fee was five cents.
Stamp dealers would have been prime mailers of light packages with minimum insurance. This envelope was presumably sent in 1954 by Mystic, as a stamp dealer would have no reason to overpay a half cent.
This portion of a wrapper does not represent a properly paid combination of third class postage with minimum insurance. It was mailed in 1942, when the combination would have cost six-and-one-half cents. The seven-cent Prexie represents a half-cent convenience overpayment.