I think those are a textured version of chips made by Chipco.
Here's a M/S Scotia Prince chip, made as a Chipco sample -- pics from the Chipguide.
(And that ferry sailed out of Portland, Maine ... in Chipco's backyard.

Also, some of the early Chipco limited editions, etc. from Harvey's & Harrah's Tahoe, El San Juan - Puerto Rico, etc. had this texture I think.
I didn't look to verify, but that's my recollection.

If you enlarge, you will see the same texture pattern.