315 is a highly effective anti-discoloration agent for gold and silver plating. For silver plating, it does not change color in the 5% K2S test for 3-10 minutes (under 25℃ conditions, the time is related to the thickness of the silver plating), and it does not change color at 260℃ for 10 minutes. There are sulfur potassium contents on the market, including 45%, 50%, 98%, etc., and there is an unknown content for blackening use. In order to ensure the accuracy of the K2S test results, it is recommended to use a content of 98%. For gold plating, it has no corrosion in a 72-hour salt spray test.
