diff --git a/examples/tools/saturation.lisp b/examples/tools/saturation.lisp
new file mode 100644
index 0000000..5bd95b0
--- /dev/null
+++ b/examples/tools/saturation.lisp
@@ -0,0 +1,16 @@
+(clear)
+; drag an image
+(import $path)
+(def original (copy))
+(defn update 
+  (e) 
+  (if 
+    (eq e:is-down true) 
+    (
+      (paste original) 
+      (def val (div e:x 400)) 
+      (pixels saturation val) 
+      (guide (line e:x 0 e:x 900)) 
+      (fill (text 88 580 40 val) "white"))))
+; add interaction
+(on "mouse-move" update)
\ No newline at end of file