“Brush, ink, paper and stone: the four treasures of ink art. But Wei Tang believed that one of them shone brightest. They say that Wei Tang did not have a good character. He was dully, genially closed in his own thoughts. Some believed that he was stupid, because he did not greet or bow in front of princes and officials. He was an alchemist, a craftsman and an artist. He made the best brushes in China, made from several concentric layers of hair of different lengths, arranged around a central core that served as a reservoir. His kōgō had stiff bristles, made from horse, deer, badger, fox or rabbit hair; nangō were made from goat hair and were soft. His brushes were said to be on par with those of the great Meng Tian, ​​made from camel hair, both soft and stiff. Wei Tang was not satisfied, although his care was proverbial. He was convinced that the problem was in the ink formula: the black wasn't deep enough, and the consistency was too lumpy. He was so convinced of this that he refused to use the ink that the emperor himself had given him. A scandalous gesture, since the emperor's ink had great value: the subjects gave it to their princes, and in the army it was used for writing but also to treat wounds and inflammatory diseases. Wei Tang went straight on his way.

They then say that the day came when his efforts got their just reward. By burning pine and ash wood under a funnel and condensing the smoke on a rigid cover, he obtained a very black powder which he then brushed into a container. To make it compact, he added a mixture of glue, made from animal horns, and sesame oil. Then, as per tradition, he dried the mixture into elongated and solid sticks. By rubbing it on a hollowed out stone, the hard material turned back into dust and mixed with pure spring water, leaving the precious ink on the concave part of the stone. It was finally the deep black he wanted."

This was told by the Zen monks who brought the art of ink painting to Japan from China. There must have been something true about the great quality of Wei Tang's invention, given that Xiao Ziliang, prince of the south during the Qi dynasty, wrote that that ink was better than lacquer...

The fascinating technique of Japanese ink painting is described in the original book Sumie – the Japanese art of ink painting , written and illustrated by the master Shozo Koike (in collaboration with Raffaella Costanzo and Anna Cristina Alves Moreira). The illustrations in the article are taken from this volume.