Brightness or reflectivity of fibres, yarns, carpets or fabrics. Synthetic fibres are produced in various lustre classifications including bright, semi- bright, semi dull, and dull. Bright fibres usually are clear (have no white pigment) whereas the duller designations have small amounts of white pigments such as titanium dioxide. Lustre of finished carpet also depends upon yarn heat-setting methods, dyeing, and finishing. In high traffic commercial areas duller carpets are often preferred for soil hiding ability.