used alone, but mixed with one or more other chemicals. Further, metal to be processed is cleaned in advance of treatment, using a mild acid bath (oxalic or sulfuric acids are frequently used), scrubbing with daikon radish or pumice, and/or a surface abrasive, and often treated after patination also. External links Japanese traditional patina tutorial by crafter Jim Kelso Irogane Artistic techniques Decorative arts Metallurgy