Whiteboard
Albert Stallion invented whiteboards while working at Alliance in the 1960s. Alliance (now known as PolyVision) produced enameled steel for architectural cladding, but Stallion noted it could also potentially be used as a writing surface. Stallion later left Alliance to form his own whiteboard production company, MagiBoards.
Black Jack (stamp)
After the War was over, poverty inspired people to wash off the cancellation from the stamps and attempt to use them again. The Government then decided to put an antitheft device onto the stamps known as a grill. This grill, which consisted of various rows of tiny indentations into the stamps, was supposed to make it impossible to wash off the cancellations without being detected; but people usually got around this by bisecting the stamp, and then reusing that portion that didn't have a cancellation on it. The first grill applied to a Black Jack stamp is known as the "Z" grill, introduced in January 1868. Over the next few months, the Post Office successively employed three smaller grill patterns (D, E and F) in the production of this stamp.