Unlike carpets, upholstered furniture contains various filler materials under the fabric. These would also absorb the product solution after an application with the Carpet Stain Remover. The active ingredients in the formula have dirt-binding properties. After the treatment, it is therefore important to fully dab out the product residues in addition to the stain residues. This is difficult to do on upholstered furniture. However, if active substances remain in the fabric they will bind pollutions such as dust etc. A dark spot would appear after a certain period of time.