stain

A stain is a discoloration or mark that occurs when a substance, such as food, drink, or dirt, penetrates and bonds with a material’s surface, like fabric or upholstery. It often results in an unwanted, often permanent, change in appearance. Stains can vary in color, size, and cause, and some materials are more resistant than others. Effective removal depends on the type of stain and the material involved. Recognizing how a stain interacts with surfaces helps in choosing the right cleaning method to restore the item’s original look.