Our 20 gauge Bare Copper Artistic Wire has not been treated with any anti-tarnish or additional coatings, so it is ideal for adding your own patina, or letting it naturally age and darken over time. Because this is bare copper wire, it can be used with heat or soldering as the color will not transition as severely as it would with Natural Copper Artistic Wire. This wire is perfectly suited for beading or wire wrapping projects due to its softness and flexibility.