A particulate material added before extrusion to subdue the lustre of a man-made fibre
Note 1 : The anatase form of titanium dioxide is commonly used for this purpose
Note 2 : Terms used to indicate the level of delustrant in man-made fibres include: clear, bright, semi-dull, semi-matt, dull, matt, extra dull, and super dull
see also lustre
Textile Resource (http://www.textile.org.uk)