BARE copper by Artistic Wire is solid copper and will patina, solder, and bend softly as such.Twenty Standard Colors and a variety of rich metallic and soft matte finishes. Choose colors that complement one another to achieve warm, colorful designs. Non-tarnish brass resembles gold & will retain its finish and shine due to our proprietary non-tarnish coating. Tinned Copper and Bare Copper do not have a tarnish-resistant coating so they will patina, or naturally oxidize and darken, with time to provide a vintage look. Stainless Steel is not copper. Choose Grey if looking for stainless steel color in a copper wire. Colors are acid-free.