Travelling salesman's stuff (3)
I believe the answer is:
rep
This clue is a double definition.
'travelling salesman's' is the first definition.
(I've seen this before)
'stuff' is the second definition.
(I've seen this before)
(Other definitions for rep that I've seen before include "Sort of theatre" , "what a draper usually sells" , "Corded fabric" , "Corded cloth for short theatrical group" , "Theatre; fabric; salesman" .)