A capsule covering the cork, usually with an imprint indicating the wine or producer. This capsule is the upper part of a foil that tightly encloses the neck of the bottle. This protects the cork from drying out, from contamination with e.g. bacteria and from infestation by the cork moth and its egg-laying, and also slows down the OTR rate (gas exchange) between the bottle contents and the outside world or the entry of oxygen. Last but not least, this also serves a decorative purpose. The capsule can be made of different materials. The formerly common toxic lead capsule, which was trivialized and called tinfoil capsule (originally an alloy of lead and silver), is now forbidden in viticulture. Today, the capsules are made of neutral, non-toxic tin (also known as tinfoil), aluminium, which is much cheaper but does not fit as tightly to the neck of the bottle, but also, especially for simple wines, of plastics such as PET, polyethylene, PVC or PVDC.