diff --git a/theme/theme.go b/theme/theme.go
index 769c8b7..eff93a3 100644
--- a/theme/theme.go
+++ b/theme/theme.go
@@ -47,27 +47,32 @@ func (id Color) RGBA () (r, g, b, a uint32) {
 
 // Theme is an object that can apply a visual style to different objects.
 type Theme interface {
+	// A word on textures:
+	//
+	// Because textures can be linked to some resource that is outside of
+	// the control of Go's garbage collector, methods of Theme must not
+	// allocate new copies of a texture each time they are called. It is
+	// fine to lazily load textures and save them for later use, but the
+	// same texture must never be allocated multiple times as this could
+	// cause a memory leak.
+	//
+	// As such, textures returned by these methods must be protected.
+	
 	// Apply applies the theme to the given object, according to the given
 	// role. This may register event listeners with the given object;
-	// closing the returned cookie will remove them.
+	// closing the returned cookie must remove them.
 	Apply (tomo.Object, Role) event.Cookie
 
 	// RGBA returns the RGBA values of the corresponding color ID.
 	RGBA (Color) (r, g, b, a uint32)
 
-	// Icon returns a texture of the corresponding icon ID. This texture
-	// should be protected, unless a new copy of it is returned with each
-	// subsequent call.
+	// Icon returns a texture of the corresponding icon ID.
 	Icon (Icon, IconSize) canvas.Texture
 
-	// MimeIcon returns an icon corresponding to a MIME type. This texture
-	// should be protected, unless a new copy of it is returned with each
-	// subsequent call.
+	// MimeIcon returns an icon corresponding to a MIME type.
 	MimeIcon (data.Mime, IconSize) canvas.Texture
 
-	// ApplicationIcon returns an icon corresponding to an application. This
-	// texture should be protected, unless a new copy of it is returned with
-	// each subsequent call.
+	// ApplicationIcon returns an icon corresponding to an application.
 	ApplicationIcon (ApplicationIcon, IconSize) canvas.Texture
 }