An area of detailing that most detailers struggle with is stain removal from interior fabrics and fibers. One thing every detailer needs to know is that there are different types of fibers found inside the cars.
Detailers need to remember that there are fibers that are less susceptible to staining than others. One of the fibers is nylon which is fortunate because nylon is the fiber most used in automobile interiors. Nylon’s soft-texture resists most food and beverage stains, and some oil-based stains. Additionally nylon fibers are also easy to clean and only absorb about seven percent of moisture.
Stains on non-resistant fibers penetrate into little holes in the fibers called dye sites. Coffee for example, gets into these boles and dries. Eventually the stain seeps up from the dye sites and comes to the surface.
Sometimes after you have spot-treated a stain and shampooed the carpets /upholstery the stain will reappear in a few days. This is called “wicking.” It is sometimes necessary to go over a stain two or three times to truly remove it so that it will not reappear.