Six Column Symmetry
Harmony Worldwide · Even / Odd Column Mirror · Christopher Seekins
Six Column Mirror Symmetry · Even columns (6,8,10,12,2,4) on the left · Odd columns (7,9,11,1,3,5) on the right · All elements share the same class position on both sides except He(2), Do(119), Ci(120), Ps(121), as well as the elements outlined in orange, which hold sequential positions though shift within the columns.