"Match Game: Strategies for Avoiding Brick Blending Problems," by Niklas W. Vigener and Philip Frederick, Masonry Construction, July 2010
Brick masonry is one of our most widely used building materials and has been used to construct building facades for thousands of years. Because brick is manufactured from natural materials, and with firing processes that produce a nonuniform temperature distribution across a cube of brick, brick masonry from the same plant, product line, and even from the same batch and production run will have variations in color and, occasionally, surface texture.