50 x 50 x 1 3/4 inches (127 x 127 x 4.4 cm)
White, wall-mounted array of 1,296, 1″-wide (x 1″-tall +”x 5/8″-deep), square, recesses, each separated by .375″, a 36-x-36-square grid, top of array at 72”.
Each recess holds .875″ cube, half-painted white, half-painted black, 1,296 cubes total, 36-cubes-across, 36-cubes-down.
At start, all cubes turned so white half facing out, black half concealed.
Signed and dated on shelf in graphite
“Choosing randomly, turn cubes so black side facing out.
When all cubes black:
Choosing randomly, turn cubes so white side facing out.
When all cubes white:
Choosing randomly, turn cubes so black side facing out…
If unsure whether cubes turning black or white, choose.”