Low-temperature Coloring: Room-temperature Polysulfide Recipes
低温着色：室温多硫化合物新配方
标签：多硫化合物, 低温, 配方, 硫化物, 均匀着色, 室温
传统肝硫需加热且气味大，近年流行室温多硫化合物体系：多硫化铵（(NH₄)₂Sₓ，x=2–4）1–2 vol% 水溶液，20–25 °C 浸渍 30–90 s 得棕→紫→蓝黑梯度，比硫化钾更可控、颜色更均匀，不易出现斑驳。也可用硫代硫酸钠 20 g/L + 稀醋酸活化两步法，室温成膜速度减半但无 H₂S 刺激气味，适合室内工作室。
Room-temperature polysulfide systems are replacing heated liver of sulfur: dip in 1–2 vol% ammonium polysulfide ((NH₄)₂Sₓ, x=2–4) at 20–25 °C for 30–90 s for the brown→violet→blue-black gradient — more controllable and even than potassium sulfide, with less mottling. A two-step route (20 g/L sodium thiosulfate, then dilute acetic acid activation) works at half the speed but releases little irritating H₂S, suiting indoor studios. ---