Intended to cover postage on a letter to the United States, the 11-cent Canal Zone Seal and Jet airmail (Scott C49) was issued on September 24, 1971, in both pane and booklet pane formats. A rate increase on May 16, 1971, which made the 10-cent airmail virtually useless, prompted the issue.
None of the original 3,335 000 stamps remained on sale when the Canal Zone Postal Service closed on September 30, 1979. In fact, frantic customers purchased the few remainders at that time to be used on 'Last Day Covers'. The same was true for the 319,440 five-pane booklets.
Covers with the 11-cent Canal Zone Seal and Jet airmail are quite common. First day covers for both the pane and booklet stamps numbered about 10,900, many of which were prepared by a local stamp club. Quantities of official covers used as VIP souvenirs also exist. When used in multiples or full booklet panes and in tandem with other stamps in a 'make-up' mode, they are less frequently seen.