Core Ten weathering steel is popular among architects for it’s rusty appearance, which is caused by the actual rusting of the metal. Once the rusting starts, the metal begins to develop an orange patina, which over time can become a dark brownish color. On thick 22 gauge weathering steel panels, this corrosion can act as a protective layer preventing further corrosion. Weathering steel is aesthetically pleasing, and provides a natural-looking patina in an ultra low-gloss finish once the rusting has coated the entire fabricated metal. It is exciting to watch the transformation over time!