Light touch shown by popular Australian in film (6)
I believe the answer is:
patina
'film' is the definition.
(thesaurus)
'light touch shown by popular australian' is the wordplay.
'light touch' becomes 'pat' (I've seen this before).
'shown by' says to put letters next to each other.
'popular' becomes 'in'.
'australian' becomes 'a'.
'pat'+'in'+'a'='PATINA'
'in' is the link.
(Other definitions for patina that I've seen before include "Sheen produced by age and polishing" , "Fine layer on the surface, laid down over time" , "Surface coating that comes with age" , "Surface film formed by age" , "Film forming on bronze" .)