Shiny material (6)
I believe the answer is:
sateen
'shiny material' 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 "Glossy cotton fabric" , "Shiny cloth used for furnishings" , "Cotton fabric with a shiny finish" , "Glossy material" , "Sea net could provide a glossy fabric" .)