A bottle cap or bottle top is a closure for the top opening of a bottle. A cap is sometimes colorfully decorated with the logo of the brand of contents. Plastic caps are used for plastic bottles, while metal with plastic backing is used for glass; plastic caps are commonly made from polyethylene or polypropylene, while metal caps are usually either steel or aluminum. Plastic caps may have a pour spout. Flip-Top caps like Flapper closures provide controlled dispensing of dry products. Caps for plastic bottles are often made of a different type of plastic from the bottle.
A cork is another type of closure for the top of a bottle.
