Special set of linen said to be right, like that (9)
I believe the answer is:
trousseau
'special set of linen' is the definition.
(linen collected by a bride for marriage)
I can't explain the remainder of the clue.
(Other definitions for trousseau that I've seen before include "old packet" , "Bridal accessories" , "wedding gear" , "Linen for a bride" , "Clothes etc. collected by a bride for her marriage" .)