Darkened, mottled surface with a vintage, hand-aged character.
What it is
Acid washing is a finish made by exposing metal to an acid or chemical solution that lightly corrodes and darkens the surface. It creates a gray, mottled, vintage look, and makers often combine it with stonewashing for extra depth. Unlike acid etching, which creates a pattern in selected areas, acid washing treats the whole surface. The solution and timing depend on the maker.
How it feels in your EDC
An acid-washed piece has a dark, uneven, weathered character that feels rugged and understated. The surface is usually smooth to slightly textured, depending on any finishing after the wash. It suits people who like a used, tool-like look rather than a bright, shiny finish.
Care & aging
Acid washing is a surface treatment, so with daily carry, high spots and edges can gradually wear back to brighter metal. Many people enjoy that natural contrast. Its uneven look also helps hide small marks. Wipe it with a soft cloth, keep carbon steel pieces dry, and avoid polishing compounds that would remove the darker layer.
是什么
酸洗（Acid washing）是让金属接触酸或化学溶液，使表面轻微腐蚀并变暗的表面处理。它呈现灰色、斑驳的复古外观，品牌常与石洗结合以增加层次。与只在选定区域形成图案的酸蚀（acid etching）不同，酸洗处理的是整个表面。溶液和时长取决于品牌。
上手感受
酸洗作品呈深色、不均匀、经风历雨的质感，粗犷而低调。根据酸洗后的处理，表面从光滑到略带纹理不等。适合喜欢使用感、工具感，而不是明亮闪光表面的人。
保养与老化
酸洗只是表面处理，日常携带会让凸起处和边缘逐渐磨回较亮的金属，很多人喜欢这种自然对比。它不均匀的外观也有助于掩盖小痕迹。用软布擦拭，碳钢作品要保持干燥，避免使用会去掉深色层的抛光剂。
