diff --git a/stipple.sh b/stipple.sh
index 57138bd..afa4599 100644
--- a/stipple.sh
+++ b/stipple.sh
@@ -2,6 +2,13 @@
 
 INPUT=`realpath "${1}"`
 OUTPUT=`realpath "${2}"`
+INVERT="${3}"
+
+if [[ "${INVERT}" == "" ]]; then
+	INVERT="false"
+else
+	INVERT="true"
+fi
 
 WIDTH=404
 HEIGHT=374
@@ -42,7 +49,8 @@ for png in "${INPUT}/"*.png ; do
 		--line $LINE \
 		--fill $FILL \
 		--maxParticles $MAXPARTICLES \
-		--mode $MODE
+		--mode $MODE \
+		--invert $INVERT
 	rm "${tmp}"
 	cd ~/src/animation/
 	if [ "${MODE}" != "tsp" ]; then