Characteristics of Carpet Stains   When it comes to stains on carpets, there are typically two types of stains on carpets. There are surface stains and there are deep stains. Surface stains are the result of substances like dirt, grease, sap, or other stains related to foot traffic, or small stains resulting from small spills. These stains are usually just on the surface or face yarns of the carpets. Since these stains are surface orientated, they will clean off fairly easily unless they ...