Dead soft square copper wire.
Square wire is great for various applications. Heavier gauges such as 1.3 mm (16 ga) to 2.6 mm (10 ga) are great for frame and structural work as well as bangle design. Smaller gauges such as 0.6 mm (22ga) to 1 mm (18ga) are are great to use for detail in your wire weaving, frame binding and various stone set