US Patent 9452560 Multilayer article with variegated appearance

A variegated capstock for covering a substrate for a building product has polymeric streaks in a non-clear, non-opaque matrix. Rapid cooling of the matrix minimizes formation of crystallites, such that the polymeric streaks become visible through a surface of the non-opaque matrix. The streaks are visible by having a color or an index of refraction different from that of the matrix. The matrix is in one or more layers, and the polymeric streaks are in the layers. The substrate is visible through the non-clear, non-opaque matrix and can appear partially obscured by the non-clear, non-opaque matrix.