Match Marking. An operation performed on colored uppers, except black, to get different parts of the upper the same shade and color, and both shoes in the pair alike.
Mat. A term applied to a dull finish kid as distinguished from glazed.
McKay Sewed or McKay. A shoe in which the outsole is attached to the insole and upper by a method named for the inventor.
McKay Sewing. Sewing through and through so that thread is seen inside of shoe.
Middle Sole. Any sole between outsole and insole.
Mock Welt. McKay-sewed shoe with a double sole and having a leather sock lining. It is fair stitched to imitate a welt.
Monkey Skin. A peculiar grained skin, and is considered in the trade as a fancy leather. It is often imitated.
Morocco. A name applied to leather originally made in Morocco. It is a sumac-tanned goatskin, red in color, and is used in book binding. The name is also applied to a leather made in imitation of this, and to heavy, plump goatskins used for shoes.
Molding. Shaping the sole to fit the bottom of last.
Mules. The name applied to slippers with no counters or quarters.