diff --git a/tasks/make-semi-transparent-background.sh b/tasks/make-semi-transparent-background.sh
new file mode 100755
index 000000000..37acc64a6
--- /dev/null
+++ b/tasks/make-semi-transparent-background.sh
@@ -0,0 +1,7 @@
+#!/usr/bin/env zsh
+for fic in $@; do
+  tmp=${fic:r}-old.${fic:e}
+  mv $fic $tmp
+  convert -background 'rgba(255,255,255,0.66)' -fill white -channel Alpha -evaluate Add 0.5 -flatten $tmp $fic
+  \rm -f $tmp
+done