The 13-cent Canal Zone Seal and Jet Airmail (Scott C-50) was issued in regular pane and booklet formats on February 11, 1974, in anticipation of the new airmail thirteen-cent rate to the United States to be effective on March 2, 1974.
Some 1,865,000 copies of this airmail stamp in pane format were printed, and all were sold prior to the close of business on September 30, 1979, after which date the Canal Zone and its postal service ceased to exist. All of the 619,000 booklet panes shipped to the Canal Zone were also sold.
Postal use of these stamps was high, and regular covers as well as first day covers are common. However, very few cachet artists were active at the time they were released. Multiples and combinations with other stamps as well as full booklet panes are less frequently seen, and many collectors find them very interesting.