diff --git a/doc/grid.png b/doc/grid.png
index 37f84e5..a84b04f 100644
Binary files a/doc/grid.png and b/doc/grid.png differ
diff --git a/doc/trees.png b/doc/trees.png
index 126b3cc..f953a73 100644
Binary files a/doc/trees.png and b/doc/trees.png differ
diff --git a/roentgen/grid.py b/roentgen/grid.py
index c8168b1..c889c85 100644
--- a/roentgen/grid.py
+++ b/roentgen/grid.py
@@ -91,13 +91,13 @@ def draw_all_icons(
         ", ".join(sorted(extractor.shapes.keys() - specified_ids)) + "."
     )
 
-    for icon in icons:  # type: Icon
+    for icon in icons:
         icon.draw_to_file(join(
             output_directory, f"{' + '.join(icon.get_names())}.svg"
         ))
 
     draw_grid(
-        output_file_name, icons, columns, step,
+        output_file_name, sorted(icons), columns, step,
         background_color=background_color
     )
 
diff --git a/roentgen/icon.py b/roentgen/icon.py
index 23f060e..3b5e96c 100644
--- a/roentgen/icon.py
+++ b/roentgen/icon.py
@@ -362,7 +362,15 @@ class Icon:
         self.shape_specifications += specifications
 
     def __eq__(self, other) -> bool:
-        return sorted(self.shape_specifications) == sorted(other.shape_specifications)
+        return sorted(self.shape_specifications) == sorted(
+            other.shape_specifications
+        )
+
+    def __lt__(self, other) -> bool:
+        return (
+            sorted(self.shape_specifications)[0].shape.id_
+            < sorted(other.shape_specifications)[0].shape.id_
+        )
 
 
 @dataclass