A matrix, or waste skeleton, describes the face material and adhesive surrounding a specialty-cut part. This material is typically removed and scrapped during the converting process. Certain adhesives and special shapes, which can not but-together without a gap, must be cut in a matrix.

Supplying parts in matrix can provide a number of process benefits. The gap between parts provides an exposed edge to grasp, easing part removal in hand assembly processes. For automated assembly, the matrix can be used to control, often critical, part to part spacing.