I keep seeing terms such as straight-across match , drop match and even random match . On all wallcovering, except some textures and murals, there is what is called a pattern repeat. This is the vertical distance between one point on a pattern design to the identical point vertically. This pattern repeat is an integral part of the design. A random match is one in which the pattern matches no matter how adjoining strips are positioned.
Stripes are a good example.
A straight-across match is one in which the design elements match on adjoining strips. A drop match is one in which there is a vertical drop between the matching design elements. With straight-across matches, every hung strip is the same as the ceiling line. With drop matches, the number of strips hung before a strip is repeated is dependent on the type of drop match. Here are illustrations of three types of matches.