Copper will be chelated (forming a complex, which is soluble into water): in another words, it will dissolve the copper. However: most dyes are slightly acid and can attack copper as well. I can hardly believe the print head contains copper, as copper can react with water to form copper hydroxide (remember those ancient bronze statues (contains copper) in water, which turned green. Even exposed to air, copper will sooner or later turn greenish). Unless Epson's policy is to optimize the razor blade business model. Ink itself is slightly acid or alkaline (depending on the type of ink). I can hardly believe that copper is used, as it will form green crusts inside the capillary ink channels very quickly, causing massive clogging. For electronic contacts of the print head having copper: yes and very plausible (good conductor), but inside the print head: to me this sounds like an urban legend