Cork is an impermeable, buoyant material, a prime-subset of bark tissue that is harvested for commercial use primarily from Quercus suber (the Cork Oak), which is endemic to southwest Europe and northwest Africa. Cork is composed of suberin, a hydrophobic substance, and because of its impermeability, buoyancy, elasticity, and fire resistance, it is used in a variety of products, the most common of which is for wine stoppers. Portugal produces approximately 50% of cork harvested annually worldwide, with Corticeira Amorim being the leading company in the industry. Cork was examined microscopically by Robert Hooke, which led to his discovery and naming of the cell.

Als Kork (Phellem) wird in der Botanik die Zellschicht zwischen Epidermis und Rinde bezeichnet. Im Alltagsgebrauch wird mit dem Begriff Kork das Material aus der Rinde der Korkeiche (Quercus suber) bezeichnet, aus dem vor allem Korken gewonnen werden. Kork wird zudem aus der Borke des asiatischen Amur-Korkbaums (Phellodendron amurense) gewonnen.

Le liège est un matériau présent dans l'écorce de quelques arbres, et notamment celle du chêne-liège. Il protège l'arbre des insectes, du froid et des intempéries tout en lui permettant de respirer, par de minces canaux appelés lenticelles.

Kork är ett material bestående av korkekens bark.

Il sughero è l'epitelio che riveste il fusto delle piante legnose nelle quali sostituisce l'epidermide, che viene lacerata dall'accrescimento secondario (diametrico) del fusto stesso. Particolarmente pregiato commercialmente è quello della quercia da sughero (Quercus suber). Il sughero viene prodotto dal fellogeno, un parenchima secondario.