Via Waxy, we are lured down a deep rabbit hole on the subject of commercial signage that are especially ubiquitous in the US, bas relief and embossed vacuum or thermo-formed pan-faced signs that go by various trade names with this appreciation of their origin and design from Beth Matthews.
Appearing in the 1950s after the novelty of neon was replaced by the durability and low cost of moulded plastic, the spread of the new format can be credited to a salesman in Los Angeles, Conrad Escalante, who developed and patented the layout of standard variants seen on guest lodgings, salons, repair shops, eateries and other businesses in need of a shingle. The docent then conducts us on a tour to see iconic examples in the wild. More at the links above.