Interpreting the solution of a Principal Component Analysis of a three-way array is greatly simplified when the core array has a large number of zero elements. The possibility of achieving this has recently been explored by rotations to simplicity or to simple targets on the one hand, and by mathematical analysis on the other. In the present paper, it is shown that a p×q×2 array, with p>qgreater-or-equal, slanted2, can almost surely be transformed to have all but 2q elements zero. It is also shown that arrays of that form have three-way rank p at most. This has direct implications for the typical rank of p×q×2 arrays, also when p=q. When pgreater-or-equal, slanted2q, the typical rank is 2q; when q
q, but it is p when p=q.