Wood – plastic. Stone – vinyl. Pine – teak. Painted – stained. Stone – concrete block, Copper – steel. Cedar shingles – vinyl siding. Think about the effect of these relationships. In each pair, there is some level of contrast that makes you feel something. In some cases, it is natural versus artificial. In others it’s real vs. fake or light vs. heavy- or even warm vs. cool. Materials matter. We choose them carefully for their texture, color, durability, and cost.