Shu Nurippanashi is built on a black urushi middle layer, on which only two top layers of red coatings are painted. The black color influences the red color towards a darker red. Actually, the back layer is slightly visible through the red layer. At the edges, top, and end parts the black urushi is more visible. It creates a finish that resembles Negoro-Nuri lacquerware. The red urushi has been mixed with a bit of oil to bring out the natural luster of urushi. It can not be polished (Nurippanashi), and so it gets its subtle satin finish.
Negoro Nuri is a lacquer technique from the 14th century: black lacquer over red or vice versa. Artifacts made from this technique are highly coveted amongst collectors. With use over time, the red or black topcoat will wear slightly, revealing some parts of the underlying base creating a genuine ‘Wabi-Sabi’ product, unique to the user. If this will happen with your pen? I’m not sure but it makes the shu-nurippanashi finish definitely special.