Sulfide: Principle & Color Gradient
硫化物着色：原理与颜色梯度
标签：硫化物, 原理, 颜色梯度, 教程
硫化物着色利用硫与铜银反应生成深色硫化物膜，同一溶液靠**时间**产生梯度：数秒浅棕→紫红→蓝→黑。控制要点：①低浓度+低温→反应慢、易控 ②分段取出水洗定色 ③热工件蘸液（热敷）可加速并偏暖棕 ④薄硫化后局部打磨露高光，形成"做旧磨损"层次。银器梯度为香槟→灰→黑。膜稳定但怕手汗摩擦，须封护。
Sulfides form dark sulfide films; with one solution **time** gives the gradient: seconds = light brown → purple-red → blue → black. Control: ①low concentration + low temp = slow, controllable ②remove in stages, rinse to set ③hot metal + solution (hot-pack) speeds it and warms toward brown ④thin sulfide then locally buff highlights for a "worn antique" look. Silver goes champagne→gray→black. Stable film but wears from handling — seal it. ---