I’m actually not sure how commonly people might encounter this outside of the Bay Area or California, but since I’ve worked on a lot of Bay Area artists’ stuff as an archivist, I’ve encountered it a lot:
For many years, I wondered about this little edge marking. As far as I can recall, I’ve come across it exclusively in color reversal film, and early on, I thought it might be a stock edge code of some kind, indicating a particular Eastman Kodak stock. But this quickly seemed unlikely, and for years I really wasn’t sure. In 2016, I unexpectedly found the answer to my very obscure question, when I inspected a 16mm film with this leader spliced to its head:
Highland Laboratories was, as you can see, a San Francisco film lab used by many 16mm filmmakers (especially Bay Area folks) for processing. It’s not unheard of for an independent film lab to expose a little logo or bit of text in the edges of film they process, but the intriguing graphical nature of this particular logo was suggestive of other possible interpretation, and as a result was mysterious to me for years (and I’ve spoken to at least a couple of archivist friends who’ve also encountered it and been befuddled by it).
As a film lab, the company is defunct. The trademark registration paperwork for the logo (registration number 0784586, filed by the lab’s owner, Barry J. Brose) indicates it was first used 3/30/1961, filed for trademark 2/12/1964, officially registered as a trademark 2/2/1965, and declared “dead/expired” on 5/2/1985.
LIGHTSTRUCK 