| 摘要 |
The invention provides an ink composition comprising a silver colloid and an antitarnish agent for preventing discoloration of silver. Despite the use of a silver colloid which is likely to discolor, as a colorant, discoloration of the printing face in a relatively short period can be prevented, and good metal gloss of the printing face can be maintained over a longer period of time than that attained by the prior art technique.
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