LeWitt (1968) x Conway (1970)
Tue 14 Apr 2015 12:13 PM
Divide a wall into a square grid. Mark arbitrary grid elements with a horizontal line about one-fifth of the way down in the square.
For every cell that was marked to begin with, if it is adjacent to two or three marked squares, mark it with another horizontal line about two-fifths of the way down in the square.
For every unmarked cell, mark it with a line if exactly three of the adjacent grid elements are marked.
Repeat with lines horizontal lines three-fifths of the way down, based on the previous lines.
Continue for a total of twenty sets of lines: The fifth set of lines will be at the bottom of the squares. For the sixth set of lines, mark vertical lines one-fifth of the way across the square... and so on. For the eleventh set of lines, mark diagonal lines one-fifth of the way across. For the sixteenth set, mark diagonal lines which slope in the other direction.