Source : Webster's Revised Unabridged Dictionary (1913)

Scrim \Scrim\, n.
   1. A kind of light cotton or linen fabric, often woven in
      openwork patterns, -- used for curtains, etc,; -- called
      also {India scrim}.

   2. pl. Thin canvas glued on the inside of panels to prevent
      shrinking, checking, etc.

Source : WordNet®

scrim
     n : a firm open-weave fabric used for a curtain in the theater