MARSHALLTOWN Line Blocks make it easy to maintain a straight when laying brick and blocks for any masonry project. Our Line Blocks are available in two styles: smooth poplar hardwood or a highly visible and waterproof Plastic Line Block. This Masonry tool is also in our contractor-grade QLT brand. QLT Corner Line Blocks are made of cast aluminum and are ideal for creating sharp corners. Our MARSHALLTOWN brand Masonry Line Blocks are Made in the USA with Global Materials.