Decorative material (6)
(Other definitions for tinsel that I've seen before include "Christmas tree decoration" , "Inexpensive sparkly stuff" , "Sparkly strands" , "Showy decoration" , "At Christmas it might be seen" .)
'decorative material' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for lace that I've seen before include "Flimsy fabric or shoe fasterner" , "Shoe tie" , "Do up (shoe, etc)" , "Delicate open-weave fabric" , "Shoe string" .)