In the 1910s, Waterman gave out these quite unusual "Knock Wood" coins to anyone who wrote in and asked. On the front it says, "Waterman's Ideal Fountain Pen," and around the edge, "Utopian State Seal - Sovereign Talisman Against All Evil"
The reverse has a very thin veneer of wood which you would touch or "knock" for good luck. It says “Knock Wood," and around the edge it reads, "The Royal Currency of Utopia."
The coins came in white (pictured), black, blue and red. White is said to be the most rare.