It has to do with spirituality, symbolism, and tradition. It symbolizes putting a part of four peoples spirit into woodcut. It is a tradition for all four people to put their spirit into it.
The Japanese woodcut prints were created by a collaboration between four people: an artist, a publisher, a printer and a block cutter.
This print is known as ukiyo-e prints. It involved the division of labor as the Printer printed with water inks, the Publisher financed, the block cutter carved blocks and the artist drew the colors.
For the diversity of arts maybe. Because he feels like it.
Hmm, it would have to be either satin or silk. I am not sure which exact one. I've looked it up but can't find much. So, it's either C or D since they are both shiny
