diff --git a/painter.py b/painter.py
index e196f13..9a121aa 100644
--- a/painter.py
+++ b/painter.py
@@ -101,6 +101,15 @@ class Painter(Widget):
                 self.unselected=[]
                 self.draw()
 
+            # toggle grid
+            elif keycode[1]=="g":
+                for particle in self.selected:
+                    if particle.grid==0:
+                        particle.grid=1
+                    else:
+                        particle.grid=-particle.grid
+                self.draw()
+
     def on_key_up(self, keyboard, keycode):
         if keycode[1]=="shift":
             if 's' in self.modifiers: