Plaster base (4)
I believe the answer is:
lath
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">plaster base</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 lath that I've seen before include "Plaster-supporting wood strip" , "Narrow strip of wood used as backing for plasterwork" , "Thin wood strip supporting plaster" , "Narrow thin strip of wood" , "Thin strip of wood used in plastering" .)