NK: Thanks to Kerry Millar who writes: "NK stands for Nadav Kandar, a world-renouned photographer and close friend of Dario's. According to his tweet Nadav bought a frame from Dario back in 2010 so I don't know if Dario created the original paint scheme for Nadav and then opted to replicate it for others, or if Nadav's artwork was an inspiration for him like so many other influences."