LEFT ONE QUARTER BLOCK
UPPER HALF BLOCK
LOWER SEVEN EIGHTHS BLOCK
LEFT THREE EIGHTHS BLOCK
RIGHT HALF BLOCK
MEDIUM SHADE
DARK SHADE
QUADRANT UPPER LEFT AND LOWER LEFT AND LOWER RIGHT
QUADRANT UPPER LEFT AND UPPER RIGHT AND LOWER LEFT
QUADRANT UPPER LEFT AND UPPER RIGHT AND LOWER RIGHT
QUADRANT UPPER RIGHT AND LOWER LEFT AND LOWER RIGHT