From at least the late 1960s, law firms and banks produced Lucite slabs that encased the tombstone ads announcing new partner classes. By the early 1970s, deal closings were being similarly immortalized.
In the late 1960s, law firms and banks started creating Lucite encasements for tombstone-style advertisements announcing new partner classes. By the early 1970s, important business deals were being similarly recorded in this way.