The opposite is partitioning, the use of methods to create segments from entire sets, most often through registral difference.
In music using the twelve-tone technique a partition is "a collection of disjunct, unordered pitch-class sets that comprise an aggregate".
A cross-partition is, "a two-dimensional configuration of pitch classes whose columns are realized as chords, and whose rows are differentiated from one another by registral, timbral, or other means.
"[4] This allows, "slot-machine transformations that reorder the vertical trichords but keep the pitch classes in their columns.
"[4] A mosaic is "a partition that divides the aggregate into segments of equal size", according to Martino (1961).