Safer to have 16 ounces only used for sparring. Guys in my gym who don't have their own borrow gym's gloves for sparring and buy gloves for the bag that are 10 or 12 ounce. The foam in bag gloves is layered but in sparring or fighting gloves it's moulded. Moulded foam is nicer for your opponent's head but won't last long on the bag.