diff --git a/output/src/out_impls.rs b/output/src/out_impls.rs
index 755d152..34b9f47 100644
--- a/output/src/out_impls.rs
+++ b/output/src/out_impls.rs
@@ -204,8 +204,8 @@ impl Direction {
     }
 }
 
-impl<E: Out, T: Has<Measure<E>>> HasSize<E> for T {
-    fn size (&self) -> &Measure<E> {
+impl<E: Out, T: Has<Measure<E>>> Measured<E> for T {
+    fn measure (&self) -> &Measure<E> {
         self.get()
     }
 }
diff --git a/output/src/out_traits.rs b/output/src/out_traits.rs
index b004012..39abe19 100644
--- a/output/src/out_traits.rs
+++ b/output/src/out_traits.rs
@@ -134,6 +134,8 @@ pub trait HasWH<N: Coord> {
 }
 
 // Something that has a 2D bounding box (X, Y, W, H).
+//
+// FIXME: The other way around?
 pub trait HasXYWH<N: Coord>: HasXY<N> + HasWH<N> {
     fn x2 (&self) -> N { self.x().plus(self.w()) }
     fn y2 (&self) -> N { self.y().plus(self.h()) }
@@ -147,9 +149,9 @@ pub trait HasXYWH<N: Coord>: HasXY<N> + HasWH<N> {
     }
 }
 
-// TODO DOCUMENTME
-pub trait HasSize<O: Out> {
-    fn size   (&self) -> &Measure<O>;
-    fn width  (&self) -> O::Unit { self.size().w() }
-    fn height (&self) -> O::Unit { self.size().h() }
+// Something that has a [Measure] of its rendered size.
+pub trait Measured<O: Out> {
+    fn measure        (&self) -> &Measure<O>;
+    fn measure_width  (&self) -> O::Unit { self.measure().w() }
+    fn measure_height (&self) -> O::Unit { self.measure().h() }
 }