diff --git a/CHANGES b/CHANGES
--- a/CHANGES
+++ b/CHANGES
@@ -1,4 +1,26 @@
 
+0.22.0 TO 0.23.0:
+ 
+  * @Basic.GraphicsState@ - extracted the font face fields from 
+    @FontAttr@ datatype into a separate datatype @FontFace@.
+ 
+  * Added @PtSize@ a numeric type wrapping Double. This is 
+    specifically for text size calculations, vis the 
+    @Core.FontSize@ module.
+
+  * Changed all functions in @Core.FontSize@ to return @PtSize@
+    instead of a polymorphic type @u@ (where @u@ is an instance 
+    of Fractional). To get to another unit type rather than 
+    FontSize use an explicit conversion that scales the value 
+    accordingly.
+
+  * Added FromPtSize class constraints to various functions in
+    @Core.Picture@.
+
+  * Added @charWidth@ to @Core.FontSize@.
+
+  * Added @vlength@ to @Core.Geometry@
+
 0.21.0 to 0.22.0:
 
   * Moved the deprecated module @Wumpus.Extra.PictureLanguage@
diff --git a/demo/FontMetrics.hs b/demo/FontMetrics.hs
--- a/demo/FontMetrics.hs
+++ b/demo/FontMetrics.hs
@@ -28,7 +28,7 @@
 black = RGB3 0 0 0 
 
 courier_attr :: FontAttr
-courier_attr = FontAttr "Courier" "Courier New" SVG_REGULAR 48
+courier_attr = FontAttr 48 (FontFace "Courier" "Courier New" SVG_REGULAR)
 
 metrics_pic :: DPicture
 metrics_pic = char_pic `picOver` lines_pic
@@ -55,7 +55,7 @@
 type PrimF = DPoint2 -> DPrimitive
 
 bodyHeight  :: PrimF
-bodyHeight  = vertLine peru courier48_numeral_height
+bodyHeight  = vertLine peru $ fromPtSize courier48_numeral_height
 
 agraveU     :: PrimF
 agraveU     = textlabel (black, courier_attr) "&#Agrave"
@@ -67,9 +67,9 @@
 vertLine :: DRGB -> Double -> DPoint2 -> DPrimitive
 vertLine rgb height pt = ostroke rgb $ vertexPath [pt, pt .+^ vvec height]
 
-haxis :: DRGB -> Double -> DPrimitive
+haxis :: DRGB -> PtSize -> DPrimitive
 haxis rgb ypos = 
     ostroke (rgb, dash_attr) $ vertexPath [ pt, pt .+^ hvec 440 ]
   where
     dash_attr = DashPattern (Dash 0 [(2,2)])
-    pt        = P2 0 ypos
+    pt        = P2 0 (fromPtSize ypos)
diff --git a/demo/LabelPic.hs b/demo/LabelPic.hs
--- a/demo/LabelPic.hs
+++ b/demo/LabelPic.hs
@@ -11,7 +11,7 @@
 
 
 
-drawBounds :: (Floating u, Real u) => Picture u -> Picture u
+drawBounds :: (Floating u, Real u, FromPtSize u) => Picture u -> Picture u
 drawBounds p        = p `picOver` (frame $ cstroke () ph) 
   where
     ph            = vertexPath $ [bl,br,tr,tl]
@@ -44,7 +44,7 @@
 lbl1 = line1 `picBeside` line2 where
   line1 = frame (textlabel attrs "Hello" zeroPt)
   line2 = frame (textlabel attrs "World" zeroPt)
-  attrs = (peru, FontAttr "Helvetica" "Helvetica" SVG_REGULAR 12) 
+  attrs = (peru, FontAttr 12 (FontFace "Helvetica" "Helvetica" SVG_REGULAR)) 
 
 
 demo01 :: IO ()
@@ -93,7 +93,7 @@
 bigLetter :: PSRgb -> Char -> Picture Double
 bigLetter col ch = uniformScale 5 $ frame $ textlabel attrs [ch] zeroPt
   where
-    attrs = (col, FontAttr "Helvetica" "Helvetica" SVG_REGULAR 12) 
+    attrs = (col, FontAttr 12 (FontFace "Helvetica" "Helvetica" SVG_REGULAR)) 
 
 
 -- | A should be above B, above T
diff --git a/doc-src/Guide.lhs b/doc-src/Guide.lhs
--- a/doc-src/Guide.lhs
+++ b/doc-src/Guide.lhs
@@ -101,6 +101,11 @@
 width, etc. - may be specified or not. The technique is due to 
 Iavor S. Diatchki's XML-Light.
 
+\item[\texttt{Wumpus.Core.PtSize.}]
+Text size calculations in \texttt{Core.FontSize} use points 
+(i.e. 1/72 of an inch). The \texttt{PtSize} module is a numeric 
+type to represent them.
+
 \item[\texttt{Wumpus.Core.TextEncoder.}]
 Types for handling non-ASCII character codes. This module is
 perhaps under-cooked although it appears adequate for Latin-1.
diff --git a/doc/Guide.pdf b/doc/Guide.pdf
Binary files a/doc/Guide.pdf and b/doc/Guide.pdf differ
diff --git a/src/Wumpus/Core.hs b/src/Wumpus/Core.hs
--- a/src/Wumpus/Core.hs
+++ b/src/Wumpus/Core.hs
@@ -34,6 +34,8 @@
 --
 -- * "Wumpus.Core.PictureLanguage"
 --
+-- * "Wumpus.Core.PtSize"
+--
 -- * "Wumpus.Core.TextEncoder"
 --
 -- * "Wumpus.Core.VersionNumber"
@@ -42,7 +44,9 @@
 --
 -- Named colours ( black, white etc.) are hidden from 
 -- "Wumpus.Core.Colour" to avoid collisions with modules that
--- define colour sets (e.g. all the SVG colours). 
+-- define colour sets (e.g. all the SVG colours). If needed, 
+-- the module can be imported directly.
+-- 
 --
 -- 
 --------------------------------------------------------------------------------
@@ -59,6 +63,7 @@
   , module Wumpus.Core.OutputPostScript
   , module Wumpus.Core.OutputSVG
   , module Wumpus.Core.Picture
+  , module Wumpus.Core.PtSize
   , module Wumpus.Core.TextEncoder
   , module Wumpus.Core.VersionNumber
   , module Wumpus.Core.WumpusTypes
@@ -74,6 +79,7 @@
 import Wumpus.Core.OutputPostScript
 import Wumpus.Core.OutputSVG
 import Wumpus.Core.Picture
+import Wumpus.Core.PtSize
 import Wumpus.Core.TextEncoder
 import Wumpus.Core.VersionNumber
 import Wumpus.Core.WumpusTypes
diff --git a/src/Wumpus/Core/FontSize.hs b/src/Wumpus/Core/FontSize.hs
--- a/src/Wumpus/Core/FontSize.hs
+++ b/src/Wumpus/Core/FontSize.hs
@@ -44,6 +44,7 @@
 
   -- * Metrics calculation
   , widthAt48pt
+  , charWidth
   , textWidth
   , textHeight
   , numeralHeight
@@ -55,9 +56,12 @@
 
 import Wumpus.Core.BoundingBox
 import Wumpus.Core.Geometry
+import Wumpus.Core.PtSize
 
 import Data.AffineSpace                 -- package: vector-space
 
+
+
 type CharCount = Int
 type FontSize = Int
 
@@ -72,15 +76,15 @@
 --
 -- > width = 26.0 
 --
-courier48_width :: Num u => u
-courier48_width = 26
+courier48_width :: PtSize
+courier48_width = 26.0
 
 -- | The point size of a character in Courier at 48 pt.
 --
 -- \*\* Naturally the height is 48.0 \*\*.
 --
-courier48_height :: Num u => u
-courier48_height = 48
+courier48_height :: PtSize 
+courier48_height = 48.0
 
 
 
@@ -92,8 +96,8 @@
 --
 -- > numeral_height = 30.0 
 --
-courier48_numeral_height :: Num u => u 
-courier48_numeral_height = 30
+courier48_numeral_height :: PtSize 
+courier48_numeral_height = 30.0
 
 -- | The height of the body of a lower-case letter 
 --  (typically the letter  \'x\') in Courier at 48 pt. 
@@ -102,16 +106,16 @@
 --
 -- > xheight = 20.0 
 -- 
-courier48_xheight :: Num u => u 
-courier48_xheight = 20
+courier48_xheight :: PtSize
+courier48_xheight = 20.0
 
 
 -- | The depth of a descender in Courier at 48 pt.
 -- 
 -- > descender_depth = 9.0
 -- 
-courier48_descender_depth :: Num u => u 
-courier48_descender_depth = 9
+courier48_descender_depth :: PtSize
+courier48_descender_depth = 9.0
 
 -- | The depth of an ascender in Courier at 48 pt.
 -- 
@@ -127,8 +131,8 @@
 --
 -- > xheight + ascender_height == numeral_height
 --
-courier48_ascender_height :: Num u => u 
-courier48_ascender_height = 10
+courier48_ascender_height :: PtSize 
+courier48_ascender_height = 10.0
 
 
 -- | The spacing between letters printed directly with 
@@ -139,50 +143,58 @@
 --
 -- > spacer_width = 3.0
 --
-courier48_spacer_width :: Num u => u
-courier48_spacer_width = 3
+courier48_spacer_width :: PtSize
+courier48_spacer_width = 3.0
 
 
 -- | Width of the supplied string when printed at 48pt.
 --
-widthAt48pt :: Fractional u => CharCount -> u
-widthAt48pt n = courier48_width * len + courier48_spacer_width * len_sub
+-- (i.e. n chars + (n-1) spacers)
+--
+widthAt48pt :: CharCount -> PtSize
+widthAt48pt n = (courier48_width * len) + (courier48_spacer_width * len_sub)
   where
     len      = fromIntegral n
     len_sub  = len - 1.0
 
+-- | Approximate the width of a monospace character using 
+-- metrics derived from the Courier font.
+--
+charWidth :: FontSize -> PtSize
+charWidth sz = (fromIntegral sz)/48 * courier48_width
+
 -- | Text width at @sz@ point size of the string @s@. All
 -- characters are counted literally - special chars may cause
 -- problems (this a current deficiency of Wumpus).
 --
-textWidth :: Fractional u => FontSize -> CharCount -> u
+textWidth :: FontSize -> CharCount -> PtSize
 textWidth sz n = (fromIntegral sz)/48 * widthAt48pt n
 
 
 -- | Text height is just identity/double-coercion of the Point size.
 -- i.e. @18 == 18.0@. The /size/ of a font is the maximum height:
 --
-textHeight :: Num u =>  FontSize -> u
+textHeight :: FontSize -> PtSize
 textHeight = fromIntegral
 
 -- | Approximate the height of a numeral using metrics derived 
 -- from the Courier monospaced font.
 --
-numeralHeight :: Fractional u => FontSize -> u
+numeralHeight :: FontSize -> PtSize
 numeralHeight sz = textHeight sz * (courier48_numeral_height / courier48_height)
 
 -- | Approximate the height of the lower-case char \'x\' using 
 -- metrics derived from the Courier monospaced font.
 --
-xcharHeight :: Fractional u => FontSize -> u
+xcharHeight :: FontSize -> PtSize
 xcharHeight sz = textHeight sz * (courier48_xheight / courier48_height)
 
 
 -- | Approximate the descender depth for font size @sz@ using
 -- metrics derived from the Courier monospaced font.
 -- 
-descenderDepth :: Fractional u => FontSize -> u
-descenderDepth sz =  (fromIntegral sz) / 48 * courier48_descender_depth
+descenderDepth :: FontSize -> PtSize
+descenderDepth sz = (fromIntegral sz) / 48 * courier48_descender_depth
 
 -- | Find the bounding box for the character count at the 
 -- supplied font-size.
@@ -197,12 +209,12 @@
 -- For variable width fonts the calculated bounding box will 
 -- usually be too long.
 --
-textBounds :: (Fractional u, Ord u) 
+textBounds :: (Fractional u, Ord u, FromPtSize u) 
            => FontSize -> Point2 u -> CharCount -> BoundingBox u
 textBounds sz body_bl n = bbox bl tr where
-    h           = textHeight sz
-    w           = textWidth  sz n
-    dd          = descenderDepth sz
+    h           = fromPtSize $ textHeight sz
+    w           = fromPtSize $ textWidth  sz n
+    dd          = fromPtSize $ descenderDepth sz
     bl          = body_bl .-^ V2 0 dd 
     tr          = bl .+^ V2 w h
   
diff --git a/src/Wumpus/Core/Geometry.hs b/src/Wumpus/Core/Geometry.hs
--- a/src/Wumpus/Core/Geometry.hs
+++ b/src/Wumpus/Core/Geometry.hs
@@ -50,11 +50,12 @@
 
   -- * Vector operations
   , vec
-  , direction
   , hvec
   , vvec
   , avec
   , pvec
+  , direction
+  , vlength
   , vangle
 
   -- * Point operations
@@ -433,11 +434,6 @@
 vec :: Num u => u -> u -> Vec2 u
 vec = V2
 
--- | Direction of a vector - i.e. the counter-clockwise angle 
--- from the x-axis.
---
-direction :: (Floating u, Real u) => Vec2 u -> Radian
-direction (V2 x y) = langle (P2 0 0) (P2 x y)
 
 -- | Construct a vector with horizontal displacement.
 --
@@ -464,6 +460,17 @@
 --
 pvec :: Num u => Point2 u -> Point2 u -> Vec2 u
 pvec = flip (.-.)
+
+-- | Direction of a vector - i.e. the counter-clockwise angle 
+-- from the x-axis.
+--
+direction :: (Floating u, Real u) => Vec2 u -> Radian
+direction (V2 x y) = langle (P2 0 0) (P2 x y)
+
+-- | Length of a vector.
+--
+vlength :: Floating u => Vec2 u -> u
+vlength (V2 x y) = sqrt $ x*x + y*y
 
 -- | Extract the angle between two vectors.
 --
diff --git a/src/Wumpus/Core/GraphicsState.hs b/src/Wumpus/Core/GraphicsState.hs
--- a/src/Wumpus/Core/GraphicsState.hs
+++ b/src/Wumpus/Core/GraphicsState.hs
@@ -56,6 +56,7 @@
 
   -- ** Font
   , FontAttr(..)
+  , FontFace(..)
   , SVGFontStyle(..)
 
   -- ** Colour
@@ -106,7 +107,7 @@
   deriving (Eq,Show)
 
 
--- | Font name and size. Equivalent fonts have different names
+-- | Font face and size. Equivalent fonts have different names
 -- in PostScript and SVG. A PostScript font name includes the 
 -- font style (e.g. @Times-BoldItalic@) whereas an SVG font has 
 -- a name (the @font-family@ attribute) and a style.
@@ -121,19 +122,29 @@
 --
 -- See the PostScript Language Reference Manual.
 --
-data FontAttr = FontAttr { 
-                    font_name       :: String,        -- for PostScript
-                    svg_font_family :: String,        -- for SVG
-                    svg_font_style  :: SVGFontStyle,
-                    font_size       :: Int 
-                  }
-  deriving (Eq,Show)
+data FontAttr = FontAttr 
+      { font_size  :: Int 
+      , font_face  :: FontFace
+      }
+  deriving (Eq,Ord,Show)
 
+-- | 'FontFace' : @ postscript_name * svg_font_family * svg_font_style @
+--
+data FontFace = FontFace
+      { font_name       :: String        -- for PostScript
+      , svg_font_family :: String        -- for SVG
+      , svg_font_style  :: SVGFontStyle
+      }
+  deriving (Eq,Ord,Show)
+
+
+
 -- | SVG font styles - potentially a style may generate both
 -- @font-weight@ and @font-style@ attributes in the SVG output.
+--
 data SVGFontStyle = SVG_REGULAR | SVG_BOLD | SVG_ITALIC | SVG_BOLD_ITALIC
                   | SVG_OBLIQUE | SVG_BOLD_OBLIQUE
-  deriving (Eq,Show)
+  deriving (Eq,Ord,Show)
 
 type PSRgb = RGB3 Double
 
diff --git a/src/Wumpus/Core/OutputPostScript.hs b/src/Wumpus/Core/OutputPostScript.hs
--- a/src/Wumpus/Core/OutputPostScript.hs
+++ b/src/Wumpus/Core/OutputPostScript.hs
@@ -227,8 +227,8 @@
 
 
 fontCommand :: FontAttr -> WumpusM ()
-fontCommand (FontAttr name _ _ sz) = do
-    ps_findfont name
+fontCommand (FontAttr sz face) = do
+    ps_findfont (font_name face)
     ps_scalefont sz
     ps_setfont
 
diff --git a/src/Wumpus/Core/OutputSVG.hs b/src/Wumpus/Core/OutputSVG.hs
--- a/src/Wumpus/Core/OutputSVG.hs
+++ b/src/Wumpus/Core/OutputSVG.hs
@@ -174,13 +174,15 @@
 --
 label :: (Real u, Floating u, PSUnit u) 
       => LabelProps -> Label u -> SvgM Element
-label (c,FontAttr _ fam style sz) (Label pt entxt ctm) = do 
+label (c,FontAttr sz face) (Label pt entxt ctm) = do 
      str <- encodedText entxt
      let tspan_elt = element_tspan str `snoc_attrs` [ attr_fill c ]
      return $ element_text tspan_elt `snoc_attrs` coord_attrs
                                      `snoc_attrs` font_attrs 
                                      `snoc_attrs` (fontStyle style)
   where
+    style       = svg_font_style  face
+    fam         = svg_font_family face
     coord_attrs = if ctm == identityCTM then simpleLabelAttrs pt
                                         else transfLabelAttrs pt ctm
     font_attrs  = [ attr_font_family fam
diff --git a/src/Wumpus/Core/Picture.hs b/src/Wumpus/Core/Picture.hs
--- a/src/Wumpus/Core/Picture.hs
+++ b/src/Wumpus/Core/Picture.hs
@@ -71,6 +71,7 @@
 import Wumpus.Core.GraphicsState
 import Wumpus.Core.OneList
 import Wumpus.Core.PictureInternal
+import Wumpus.Core.PtSize
 import Wumpus.Core.TextEncodingInternal
 
 import Data.Semigroup
@@ -102,7 +103,7 @@
 
 -- | Lift a 'Primitive' to a 'Picture', located in the standard frame.
 --
-frame :: (Real u, Floating u) => Primitive u -> Picture u
+frame :: (Real u, Floating u, FromPtSize u) => Primitive u -> Picture u
 frame p = Single (stdFrame, boundary p) p 
 
 -- | Frame a picture within the supplied bounding box
@@ -119,7 +120,7 @@
 -- ellipse. Thus the bounding box will never reframed to a 
 -- smaller size than the /natural/ bounding box.
 --
-frameWithin :: (Real u, Floating u) 
+frameWithin :: (Real u, Floating u, FromPtSize u) 
             => Primitive u -> BoundingBox u -> Picture u
 frameWithin p@(PLabel _ _) bb = Single (stdFrame,bb) p
 frameWithin p              bb = Single (stdFrame,bb `append` boundary p) p
@@ -135,7 +136,7 @@
 --
 -- This function throws an error when supplied the empty list.
 --
-frameMulti :: (Real u, Floating u) 
+frameMulti :: (Real u, Floating u, FromPtSize u) 
            => [Primitive u] -> Picture u
 frameMulti [] = error "Wumpus.Core.Picture.frameMulti - empty list"
 frameMulti xs = multi $ map frame xs
@@ -200,18 +201,19 @@
 
 
 -- | Constant for the default font, which is @Courier@ (aliased 
--- to @Courier New@ for SVG).
--- 
--- The font size is 24 point. Note that only a handful of font 
--- sizes are available directly to PostScript / GhostScript.
+-- to @Courier New@ for SVG) at 24 point.
 --
--- To get non-standard sizes, consider drawing the text and 
--- applying a 'uniformScale'.
 --
 wumpus_default_font :: FontAttr
-wumpus_default_font = FontAttr "Courier" "Courier New" SVG_REGULAR 24
+wumpus_default_font = FontAttr 24 face 
+  where
+    face = FontFace { font_name         = "Courier"
+                    , svg_font_family   = "Courier New"
+                    , svg_font_style    = SVG_REGULAR
+                    }
 
 
+
 --------------------------------------------------------------------------------
 -- Take Paths to Primitives
 
@@ -531,7 +533,8 @@
 -- Draw the picture on top of an image of its bounding box.
 -- The bounding box image will be drawn in the supplied colour.
 --
-illustrateBounds :: (Real u, Floating u) => DRGB -> Picture u -> Picture u
+illustrateBounds :: (Real u, Floating u, FromPtSize u) 
+                 => DRGB -> Picture u -> Picture u
 illustrateBounds rgb p = p `picOver` (frameMulti $ boundsPrims rgb p) 
 
 
@@ -542,7 +545,7 @@
 --
 -- The result will be lifted from Primitive to Picture.
 -- 
-illustrateBoundsPrim :: (Real u, Floating u) 
+illustrateBoundsPrim :: (Real u, Floating u, FromPtSize u) 
                      => DRGB -> Primitive u -> Picture u
 illustrateBoundsPrim rgb p = frameMulti (boundsPrims rgb p ++ [p])
 
@@ -573,7 +576,7 @@
 -- curves - they are implemented with PostScript\'s 
 -- @arc@ command.  
 --
-illustrateControlPoints :: (Real u, Floating u)
+illustrateControlPoints :: (Real u, Floating u, FromPtSize u)
                         => DRGB -> Primitive u -> Picture u
 illustrateControlPoints rgb prim = step prim
   where
diff --git a/src/Wumpus/Core/PictureInternal.hs b/src/Wumpus/Core/PictureInternal.hs
--- a/src/Wumpus/Core/PictureInternal.hs
+++ b/src/Wumpus/Core/PictureInternal.hs
@@ -73,6 +73,7 @@
 import Wumpus.Core.Geometry
 import Wumpus.Core.GraphicsState
 import Wumpus.Core.OneList
+import Wumpus.Core.PtSize
 import Wumpus.Core.TextEncodingInternal
 import Wumpus.Core.Utils
 
@@ -599,14 +600,14 @@
 -- Note - this will calculate an approximate bounding box for 
 -- text.
 
-instance (Real u, Floating u) => Boundary (Primitive u) where
+instance (Real u, Floating u, FromPtSize u) => Boundary (Primitive u) where
   boundary (PPath _ p)        = boundary p
   boundary (PLabel (_,a) l)   = primLabelBoundary a l 
   boundary (PEllipse _ e)     = boundary e
 
 
 
-primLabelBoundary :: (Floating u, Real u) 
+primLabelBoundary :: (Floating u, Real u, FromPtSize u) 
                   => FontAttr -> Label u -> BoundingBox u
 primLabelBoundary attr (Label (P2 x y) xs ctm) = 
     retraceBoundary  (disp . (m33 *#)) untraf_bbox
diff --git a/src/Wumpus/Core/PtSize.hs b/src/Wumpus/Core/PtSize.hs
new file mode 100644
--- /dev/null
+++ b/src/Wumpus/Core/PtSize.hs
@@ -0,0 +1,57 @@
+{-# LANGUAGE GeneralizedNewtypeDeriving #-}
+{-# OPTIONS -Wall #-}
+
+--------------------------------------------------------------------------------
+-- |
+-- Module      :  Wumpus.Core.PtSize
+-- Copyright   :  (c) Stephen Tetley 2010
+-- License     :  BSD3
+--
+-- Maintainer  :  stephen.tetley@gmail.com
+-- Stability   :  unstable
+-- Portability :  GHC with TypeFamilies and more
+--
+-- Numeric type representing Point size (1/72 inch) which is 
+-- PostScript and Wumpus-Core\'s internal unit size.
+--
+-- Other unit types (e.g. centimeter) should define an 
+-- appropriate instance of FromPtSize.
+-- 
+--------------------------------------------------------------------------------
+
+module Wumpus.Core.PtSize
+  ( 
+  
+  -- * Point size type
+    PtSize
+  
+  -- * Extract (unscaled) PtSize as a Double 
+  , ptSize
+
+  -- * Conversion class
+  , FromPtSize(..)
+
+  ) where
+
+
+-- | Wumpus-Core 
+newtype PtSize = PtSize { ptSize :: Double } 
+  deriving (Eq,Ord,Num,Floating,Fractional)
+
+instance Show PtSize where
+  showsPrec p d = showsPrec p (ptSize d)
+
+
+-- | Convert the value of PtSize scaling accordingly.
+--
+-- Note - the Double instance perfoms no scaling, this
+-- is because internally Wumpus-Core works in points.
+-- 
+class FromPtSize u where
+  fromPtSize :: PtSize -> u
+
+instance FromPtSize Double where
+  fromPtSize = ptSize
+
+
+
diff --git a/src/Wumpus/Core/VersionNumber.hs b/src/Wumpus/Core/VersionNumber.hs
--- a/src/Wumpus/Core/VersionNumber.hs
+++ b/src/Wumpus/Core/VersionNumber.hs
@@ -22,7 +22,7 @@
 
 -- | Version number
 --
--- > (0,22,0)
+-- > (0,23,0)
 --
 wumpus_core_version :: (Int,Int,Int)
-wumpus_core_version = (0,22,0)
+wumpus_core_version = (0,23,0)
diff --git a/wumpus-core.cabal b/wumpus-core.cabal
--- a/wumpus-core.cabal
+++ b/wumpus-core.cabal
@@ -1,5 +1,5 @@
 name:             wumpus-core
-version:          0.22.0
+version:          0.23.0
 license:          BSD3
 license-file:     LICENSE
 copyright:        Stephen Tetley <stephen.tetley@gmail.com>
@@ -50,10 +50,7 @@
   not offer distinct functionality. Some functions were removed in 
   revision 0.17.0 and some more are likely to follow. 
   .
-  The module @Extra.PictureLanguage@ is deprecated. At some point 
-  it will be superceded by @wumpus-basic@ but this will not be soon.
   .
-  .
   \[1\] Because the output is simple, straight-line PostScript 
   code, it is possible to use GraphicsMagick or a similar tool 
   to convert Wumpus'\s EPS files to many other formats 
@@ -61,53 +58,27 @@
   .
   Changelog:
   .
-  0.21.0 to 0.22.0:
-  .
-  * Moved the deprecated module @Wumpus.Extra.PictureLanguage@
-    into the package Wumpus-Basic along with the example 
-    @Picture.hs@.
-  .
-  * Added vec as a synonym for the constructor V2.
-  .
-  * Changed some of the Core.FontSize to use better terminology. 
-    Thus some of the constants have changed. Added a new example
-    @FontMetrics.hs@ to illustrate how FontSize works. 
-    Particularly, the function @capHeight@ has been replaced with
-    the function @numeralHeight@ which has better semantics.
-  .
-  * The CTM data type and ToCTM class are now hidden in the
-    top-level import module @Wumpus.Core@. They can be accessed
-    by importing @Wumpus.Core.GraphicsState@ directly.
-  .
-  * Exposed the PSUnit type class. 
-  .
-  0.20.0 to 0.21.0:
+  0.22.0 TO 0.23.0:
+  . 
+  * @Basic.GraphicsState@ - extracted the font face fields from 
+    @FontAttr@ datatype into a separate datatype @FontFace@.
+  . 
+  * Added @PtSize@ a numeric type wrapping Double. This is 
+    specifically for text size calculations, vis the 
+    @Core.FontSize@ module.
   .
-  * Removed the Primitive instances of the Affine transformation 
-    classes. They have been replaced with special transformation 
-    functions: @rotatePrimitive@, @scalePrimitive@, 
-    @translatePrimitive@. As Primitives are not in an affine 
-    frame until they are lifted to Pictures the affine instances 
-    had ill-conceived semantics.
+  * Changed all functions in @Core.FontSize@ to return @PtSize@
+    instead of a polymorphic type @u@ (where @u@ is an instance 
+    of Fractional). To get to another unit type rather than 
+    FontSize use an explicit conversion that scales the value 
+    accordingly.
   .
-  * Due to changes to accommodate the new non-affine  
-    transformations, many of the class obligations have changed 
-    on the @unit@ of Pictures, Primitives, Bounding Boxes etc. 
-    Generally many class contexts that previously required 
-    Fractional and Ord on the unit have changed to Real and 
-    Floating.
+  * Added FromPtSize class constraints to various functions in
+    @Core.Picture@.
   .
-  * Removed demo/AffineTest04.hs - there is no longer a 
-    @rotateAbout@ operation on Primitives as they do not exist 
-    in an affine frame until they they are lifted to Pictures.
-    Added - Scaled.hs, Rotated.hs, Translated,hs.
-  . 
-  * Removed the UndecidableInstances pragma from 
-    Core.PictureInternal. It looks like Core.Geometry will always 
-    need UndecidableInstances though.
+  * Added @charWidth@ to @Core.FontSize@.
   .
-  * Removed the Ord superclass constriant from the @Stroke@ and
-    @Fill@ classes and derived operations (e.g. @zostroke@).
+  * Added @vlength@ to @Core.Geometry@
   .
   .
 build-type:         Simple
@@ -152,6 +123,7 @@
     Wumpus.Core.OutputPostScript,
     Wumpus.Core.OutputSVG,
     Wumpus.Core.Picture,
+    Wumpus.Core.PtSize,
     Wumpus.Core.TextEncoder,
     Wumpus.Core.TextLatin1,
     Wumpus.Core.VersionNumber,