what is the niello technique?

The niello technique is an ancient metalworking process where a black alloy mixture, typically made of sulfur, copper, silver, and lead, is heated and melted into engraved or etched designs on metal surfaces, usually silver or gold. Once cooled and polished, the blackened niello contrasts sharply against the polished metal background, creating striking, detailed decorative patterns. This technique has historical roots dating back to the Bronze Age and was prominently used in Roman, Byzantine, medieval European, and Renaissance art for jewelry, religious objects, and weaponry decoration. Niello is known for its tough, metallic luster distinct from enamel and mainly comes in black tones to enhance the intricacy of metal designs.