Rubbed brick, brickrubber, cutter, or malm is a soft brick made of special well-mixed fine loamy clay containing a lot of sand and baked (not burnt) in a kiln, readily sawn and rubbed to the required shape. It is used for making gauged brickarches, etc., the extremely fine joints between the rubbers being formed of lime-putty rather than conventional mortar, which would be too coarse. (Curl & Wilson, 2016) Photo from Detroit, Michigan, 2021.
