I had a sweatshirt made up at cafe press with this image on it, and wore it the first day of the Oza. It is a 9x9 go board with the face of Yilun Yang 7p embedded in the grain of the board. I did the work in Photoshop. The artwork had originally been done for a tshirt for a New Jersey Yang Workshop in 2004, and I used just the artwork to create the sweatshirt with no lettering.
To create the artwork I took a photograph I had taken at a previous Yang workshop and made it a grayscale image. I then used a posterizing filter on it to reduce it to about six shades of gray. Each shade of gray was assigned a color. Then the grain was hand drawn with a graphics tablet, then the grid was superimposed over the image. The board is actual size, so if the sweatshirt were placed flat on a table you could actually play a game on it.