Delta - Dark;  a geometric pattern of 4 right-angle-isosceles triangles in varying opacity from clear to almost black which forms a diamond.  Each side of the diamond is 1 5/8" (the hypotenuse of the triangle).  The pattern turns and repeats itself as in tetrakis square tiling or 'Union Jack' lattice.    Allows good light transmission - for total privacy considerDelta Dark Privacy, which combines this pattern with a privacy film layer.