Bronze sculptures gain their distinctive character through patination, a chemical process that alters the metal's surface. Artists achieve different patina effects through various techniques and chemical combinations.

The most common method involves applying acidic solutions to oxidize the bronze surface. Ferric nitrate creates reddish-brown hues, while cupric nitrate produces greens and blues. Sulfurated potash (liver of sulfur) yields deep blacks and browns, particularly effective for highlighting details.

Temperature plays a crucial role in patination. Some artists heat the bronze before application, which accelerates chemical reactions and creates more vibrant colors. Others use cold patination for subtler, more controlled effects. Multiple layers of different chemicals can produce complex, multi-tonal finishes.

Modern artists also experiment with household substances like ammonia vapor (for blue tones) or even buried metal techniques where soil chemicals create natural oxidation patterns. Each patina formula becomes an artist's signature, with many guarding their exact mixtures closely.

After chemical treatment, artists seal the patina with wax or lacquer to preserve the finish. This final step protects against environmental factors while enhancing the color depth. The art of patination transforms durable bronze into visually dynamic works that appear to live and breathe with changing light conditions.