diff --git a/masque/label.py b/masque/label.py
index e52e836..0c250cc 100644
--- a/masque/label.py
+++ b/masque/label.py
@@ -5,17 +5,20 @@ import numpy
 from numpy.typing import ArrayLike, NDArray
 
 from .repetition import Repetition
-from .utils import rotation_matrix_2d, AutoSlots, annotations_t
+from .utils import rotation_matrix_2d, annotations_t
 from .traits import PositionableImpl, Copyable, Pivotable, RepeatableImpl, Bounded
 from .traits import AnnotatableImpl
 
 
-class Label(PositionableImpl, RepeatableImpl, AnnotatableImpl,
-            Bounded, Pivotable, Copyable, metaclass=AutoSlots):
+class Label(PositionableImpl, RepeatableImpl, AnnotatableImpl, Bounded, Pivotable, Copyable):
     """
     A text annotation with a position (but no size; it is not drawn)
     """
-    __slots__ = ( '_string', )
+    __slots__ = (
+        '_string',
+        # Inherited
+        '_offset', '_repetition', '_annotations',
+        )
 
     _string: str
     """ Label string """
diff --git a/masque/traits/__init__.py b/masque/traits/__init__.py
index 6b1541f..a3e4361 100644
--- a/masque/traits/__init__.py
+++ b/masque/traits/__init__.py
@@ -1,5 +1,7 @@
 """
 Traits (mixins) and default implementations
+
+Traits and mixins should set `__slots__ = ()` to enable use of `__slots__` in subclasses.
 """
 from .positionable import Positionable, PositionableImpl, Bounded
 from .layerable import Layerable, LayerableImpl
diff --git a/masque/traits/positionable.py b/masque/traits/positionable.py
index 3ad93cb..2b9c02e 100644
--- a/masque/traits/positionable.py
+++ b/masque/traits/positionable.py
@@ -1,5 +1,3 @@
-# TODO top-level comment about how traits should set __slots__ = (), and how to use AutoSlots
-
 from typing import Self, Any
 from abc import ABCMeta, abstractmethod