After wearing the watch for a long time, you may notice your wrist turning black. What causes this? Whether it’s a metal or leather watch strap, there is a standard. Leather straps have specific quality requirements to prevent fading or discoloration, while metal straps, being a type of surface electroplating, only have regulations regarding the bonding strength of the electroplated layer.
What causes the wrist to darken when wearing a watch band for extended periods?
Leather straps are prone to fading and staining when exposed to moisture or soaked in water, but the inner side of most leather straps is typically lighter in color.
Stainless steel straps do not fade in color; only metal straps with coating treatments may experience discoloration, typically found in lower-end products. Electroplated straps can develop surface corrosion with prolonged use, leading to severe cases where the surface becomes pitted and green rust appears. These rust stains may also transfer to the wrist.
The primary reasons for the darkening of watch straps are dust and sweat, though this can vary depending on individual factors such as work environment, job nature, personal tendency to sweat, and the way the strap is worn.
The openwork design of the watch strap makes it more prone to “accumulating dirt.” Dust, fibers, and sweat can fill all the gaps in the strap. In summer, when the wrist sweats or gets wet, the dirt dissolves and adheres to the skin, forming black spot-like marks.
