Mat material (5)
I believe the answer is:
sisal
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">mat material</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for sisal that I've seen before include "Fibrous plant used for rope" , "Type of fibre" , "material for painter, say?" , "Plant yielding rope fibre" , "Natural fibre" .)