At Japan's Kobaien factor, a 400 year-old tradition of making the much coveted sumi ink-sticks is being kept alive by the passionate expert masters who still use the same methods, the same tools, materials and processes as their predecessors did centuries ago. From "gathering smoke" to mixing animal glue with exotic perfumes to organic drying using the finest oak dust and more than a year's worth of patience and a fully hypnotic kneading and moulding process, Kobaien still manufactures ink sticks which are perfect works of art calligraphers all over the world sometimes queue for months for.