On this day in 1858, Hymen Lipman received US Patent # 19,783 for a pencil with an attached eraser. Sure, it was later rescinded because it wasn’t a new device, but just a composite of two existing products, but we still celebrate the day as National Pencil Day.
Much later, in 2017, a Japanese teenager submitted a new puzzle themed around pencils to Nikoli magazine that quickly gained popularity, because it seemed to capture the essence of solving pencil puzzles.
Draw pencils into the grid. Each pencil must also draw a line as long as itself, so that all grid cells are used.