The general dirt on the wallpaper can be wiped with a safe bleach on a towel, and wiped with water after half an hour. If the effect is not satisfactory, you can repeat it once. For stubborn stains, use a scoop of strong detergent and add half a pot of hot water. After dilution, wipe the wall with a towel. If the wallpaper is due to the yellowing of the smoke, you can dilute it with one-third of clear water and one part of bleach and wipe it with a cloth.
wallpaper
Portable spectrophotometer,45/0 spectrophotometer,Hardware spectrophotometer
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