Sleek fabric (6)
I believe the answer is:
sateen
'sleek fabric' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for sateen that I've seen before include "Sea net could provide a glossy fabric" , "Glossy material" , "Closely woven cotton fabric resembling satin" , "Shiny cloth used for furnishings" , "Glossy cotton fabric" .)