Boxing gloves are mittens that have a separate sheath for the thumb. While wearing them, it's easy to hold a tight fist since nothing more than a thin layer of material covers the palm. The part of the mitt that covers the back of the hand and the knuckles is heavily padded and protected by tough leather selected for its smoothness and flexibility. The padded thumb sheath is tightly sewn to the rest of the mitt with hidden stitches. The mitt is secured to the hand with laces that tie around the wrist and the lower part of the forearm. Sparring gloves may attach with velcro instead of laces. During a fight, the laces should be completely covered with a layer of adhesive tape to insure that they don't flop around and injure the opponent's eye.
Contrary to popular belief, boxing gloves are not worn to protect the hand from the deleterious effects of punching. Instead, they serve several other purposes.
Their most important role is to protect the opponent's face from getting cut by a blow. A boxing glove is designed to be as smooth as possible, with no sharp edges or exposed seams. Many fights are ruled TKOs and stopped due to cuts, and without good boxing gloves many more fights would end in this manner.
Gloves also serve to keep thumbs and fingers out of the opponent's eyes. Additionally, they reduce the cauliflower-ear injuries that plague bare-knuckle fighters and some other types of contact fighters. Finally, they greatly reduce the chance that the opponent's teeth will be loosened by a punch. Modern mouthguards stop the mandibular teeth from crashing against the upper teeth, and somewhat lessen the shock to the head caused by a punch to the jaw, but they don't stop an ungloved knuckle from smashing in the front teeth.
Boxing gloves range in weight up to around sixteen ounces. When a fight is scheduled, the boxers' management will deal with the promoter, the sanctioning body (if any), and the boxing/athletic commission under whose jurisdiction the fight is being held (if any) and agree on the weight of glove that will be used during the fight. Heavier fighters generally use heavier gloves. Flyweights may use gloves as light as ten ounces, and maybe even lighter in certain parts of the world. Fighting with a weighted glove is, in itself, a safety measure since it slows the punches down.
Boxing gloves, aside from being safety equipment, are also an integral part of a boxer's defense. Fighting bare-handed is significantly different than fighting with two big pillows on your hands. A gloved fighter trains to use the gloves to hide his vulnerable chin. Defensive tactics involve the glove in trapping, catching and blocking the opponent's punches. If a boxer was forced to fight without gloves, his or her strategy would change considerably. Close-range boxing would probably be replaced by longer-range bombing and brawling since any punch thrown at the head would have a high chance of passing through the guard and scoring.
Anyone who practices punching, be it on a bag, makiwara, focus mitt, or someone else's head, needs to protect their hands from damage. Boxing gloves do not offer suitable protection. Broken or dislocated bones, strained tendons, swollen fingers and wrists, and long-term repetitive-stress injuries are common results of incautious punching training. To remain free of injury, punchers need to wrap their hands. Practice wraps are commonly made of long springy material with a thumb loop sewn in one end and a velcro adhesive on the other. However, during a fight, boxers are required to wrap the hands with inelastic gauze and adhesive tape. Handwraps keep the wrist from bending down, and keep all the delicate bones and tendons aligned properly, preventing strains and sprains and reducing the incidence of broken thumbs and the boxer's break. Boxing gloves are made to fit over handwraps and will feel uncomfortably loose over unwrapped hands.