It seems that the band was adopted at the same time as the end-papers changed in 1958; Red Sea Sharks was the first title to carry the new "gallery" of blue and white portraits, and the first to get the band.
Every cover designed thereafter was given the band - the last titles from Red Sea Sharks to Picaros, plus the 1966 re-draw of Black Island, and the two live-action movie books.
Land of Black Gold was re-drawn in 1971, but the cover design was only tweaked, not changed, so the banner wasn't added - presumably because Hergé was otherwise happy with how it looked, and didn't want it to obscure the decorative "arch".
Alph-Art (in both its versions) has a similar strip, but without the portraits and text, apart from Hergé's name. This is probably to emphasize that these books don't contain a true adventure, but an archive of work in progress, and also because as far as I know, Hergé hadn't left any indication of what the finished book's cover was going to be.
Lake of Sharks doesn't have the stripe either, but as to why not, well, I've run out of ideas...! ;-) |