Futagami's solid brass products are sprayed with atomized sandblasted, non-plated, unpainted, and have long-lasting oxidation characteristics. Compared to metal products that pursue bright over-treatment, they are still oxidized for a long time. . . Use and maintenance 1. To restore gloss, use a commercially available metal polish and a polishing cloth. 2. Copper will oxidize over time and may produce some green rust (non-toxic and harmless). Cleaning method: Mix the vinegar and the salt. After dissolving, wipe the mixture with a cloth and wipe it in the green rust. Finally, wash it with detergent and dry it with a dry cloth.