diff --git a/docs/text-sizing-protocol.rst b/docs/text-sizing-protocol.rst
index 7c2ece99b..16f0d05f0 100644
--- a/docs/text-sizing-protocol.rst
+++ b/docs/text-sizing-protocol.rst
@@ -105,7 +105,11 @@ characters and thus ends up rendering text at twice the base size.
 
 When ``w`` is a non-zero value, it specifies the width in scaled cells of the
 following text. Note that **all** the text in that escape code must be rendered
-in ``s * w`` cells. If it does not fit, the terminal is free to do whatever it
+in ``s * w`` cells. When both ``s`` and ``w`` are present, the resulting multicell
+contains all the text in the escape code rendered in a grid of ``(s * w, s)``
+cells, i.e. the multicell is ``s*w`` cells wide and ``s`` cells high.
+
+If the text does not fit, the terminal is free to do whatever it
 feels is best, including truncating the text or downsizing the font size when
 rendering it. It is up to client applications to use the ``w`` key wisely and not
 try to render too much text in too few cells. When sending a string of text
@@ -128,6 +132,13 @@ when using fractional scaling, as described below.
 
 .. note:: Text sizes specified by scale are relative to the base font size,
    thus if the base font size is changed, these sizes are changed as well.
+   So if the terminal emulator is using a base font size of ``11pt``, then
+   ``s=2`` will be rendered in approximately ``22pt`` (approx. because the
+   terminal may need to slightly adjust font size to ensure it fits as not all
+   fonts scale sizes linearly). If the user changes the base font size of the
+   terminal emulator to ``12pt`` then the scaled font size becomes ``~24pt``
+   and so on.
+
 
 Fractional scaling
 ^^^^^^^^^^^^^^^^^^^^^^^