Cor-ten steel planters have a rich, deep texture not always associated with metal, the patina ages with wonderful earthy hues to complement any location. The patina (or outer-rust layer) forms a protective barrier which does not compromise the structural integrity of the material. Cor-ten Steel oxidises to its rust finish within 3 to 9 months (depending on position and climate). During oxidisation, Cor-ten steel produces carbon run off and can stain adjacent materials like stone and concrete. After the initial reactive period Cor-ten® steel will cure and self-seal with very little to no carbon runoff. Please be aware that Cor-ten products do not come pre-weathered.