Some of these are quite strong and contrasty and very repetitive in a small scale and thus slightly migraine inducing. With the horizontal repetition they also

Some of these are quite strong and contrasty and very repetitive in a small scale and thus slightly migraine inducing. With the horizontal repetition they also mess with the angle of your eyes / distance perception (as there are multiple transpositions where they correlate perfectly). I like subtle, very random and smooth patterns a lot.