Soiling degree and cleanability of different polyester textile materials before and after impregnation with a soil release polymer (SRP) has been systematically investigated. The use of an imaging instrument for the optical roughness analysis operating on the principle of chromatic aberration allowed visualisation of a transparent SRP film on impregnated textile surfaces. Through visualisation of the SRP film and quantification of its relative area, a possible mechanism of cleanability due to impregnation with SRP is proposed.