Varnish layer (4)
I believe the answer is:
coat
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">varnish layer</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for coat that I've seen before include "Fleece" , "Overgarment" , "Warm outerwear" , "Layer of paint" , "Ulster, perhaps" .)