New Dain Silver S1 (NDS-S1) is an environmentally friendly, chromium-free, neutral aqueous anti-tarnishing treatment solution for silver, silver-alloy, and silver-plated decorative and electronic parts. It maintains electric contact resistance, solderability, and surface appearance, and is free from regulated poisonous substances. Treatment involves immersion in a 10% diluted solution at 50°C (pH 5-10) for >10 seconds, followed by ion-exchanged water rinse and warm air drying. Performance tests (e.g., (NH4)2Sx immersion, 2-month window storage) confirm its superior anti-tarnishing protection for 5-micrometer semi-bright silver plating on copper panels, outperforming untreated and competitor products.