Within ACL 4.0 and 4.2, horizontal (ACL 4.0) and vertical (ACL 4.2) stripes are not as good at differentiating between the modes as the checkerboard is for ACL 4.4. The vertical stripe in ACL 4.2 is a bit awkward because it emerges out of a failed attempt to do the checkerboard pattern. The first row of alternating colours in the checkerboard pattern emerges into vertical stripes in the 2nd row. The 2nd row starts the vertical stripes that might be followed until all of the space is filled or stopped when they notice that theirs does not look like the sample.