Cork has been used since antiquity as a bottle stopper. The impermeability of cork to liquids and gases is derived from the fact that its closed cell walls are made up mainly of suberin (a type of fatty acid). Compressibility and flexibility make cork ideal for sealing bottles. A cork bottle stopper of the proper size will act as an effective barrier to leakage or seepage of liquids. No other bottle stopper combines corks inert nature, impermeability, flexibility, sealing ability and resilience. Cork, being a natural product, is also environmentally friendly, renewable and recyclable.