(written from a Production point of view)
Leaf was an American confectionery and trading card manufacturing company which released the very first trading card set, Star Trek, in 1967. The set was only released on a limited scale due to the company's small distribution area (Ohio and Illinois), and was quickly recalled as a result of licensing issues. As such, it is extremely rare.
Leaf also released a series of chocolate candy bars, licensed by Paramount Pictures, as a promotion for Star Trek: First Contact in 1996. The bars' packaging featured most of the Star Trek: The Next Generation cast and each was imprinted with an element from the film (including a Borg sphere, the USS Enterprise-E, and Zefram Cochrane. In total, there were six wrapper designs, and seven chocolate designs released.