Cork is an impermeable buoyant material. It is the phellem layer of bark tissue which is harvested for commercial use primarily from Quercus suber (the cork oak), which is native to southwest Europe and northwest Africa. Cork is composed of suberin, a hydrophobic substance.

Auctions for wine corks sell in lots as small as 20 and as large as 500. The wine bottles usually sell for about 50 cents per bottle, but fancier bottles can fetch near $5.00 each (hint: Cobalt blue bottles!). Wine corks, however, generally sell for about 10 cents each.

Wine corks are a stopper used to seal wine bottles. They are typically made from cork (bark of the cork oak), though synthetic materials can be used.

It is a completely natural raw material, with unique properties which give it an unrivalled character. It is light, impermeable to liquids and gases, elastic and compressible, provides thermal and acoustic insulation, it is a fire retardant and highly abrasion-resistant.