I found this interesting patent application filed by Ted Scarlett, of Imprint Art Co., a.k.a., IMPKO, concerning an invention to expedite the manufacture of pennants in 1959--a half century after Repco's John Clark Udall filed his first patent for the screen printing method:
See:
https://ppubs.uspto.gov/dirsearch-pu...oadPdf/2888900
IMPKO wasn't known for making the highest quality pennants, but this idea concerning the manufacture of spines ("hems") and tassels ("ties") was interesting inasmuch as it saved time, labor, and provides further insight on how some pennants were made, like this one below, at the mid-century mark.
By the way ... how'd you like to visit Intercourse, PA??