Line a mat, manoeuvring material in layers (8)
I believe the answer is:
laminate
'material in layers' is the definition.
(laminate is a material made up of layers)
'line a mat manoeuvring' is the wordplay.
'manoeuvring' indicates anagramming the letters.
'line'+'a'+'mat'='lineamat'
'lineamat' is an anagram of 'LAMINATE'.
(Other definitions for laminate that I've seen before include "Thinly cover" , "Form in thin sheets" , "Cover with a thin layer of protective material" , "Sheet of material made by bonding two or more sheets" , "Material constructed in layers" .)