`System.Drawing.Graphics#MeasureCharacterRanges` has a hard limit of 32 `CharacterRange`s for measurement, so here's a workaround. MS has stated they have no intention of fixing this, so get used to it, kids. http://connect.microsoft.com/VisualStudio/feedback/details/96250/setmeasurablecharacterranges-crashes-with-more-than-32-characters#tabs

MeasureAllCharacterRanges.vb

' This document is free and open-source software licensed simultaneously under the MIT License,
' the GPL v2, and the two-clause BSD License.

Public Function MeasureAllCharacterRanges(ByVal g As Graphics, ByVal txt As String, ByVal font As Font, ByVal dest As RectangleF,
                                          ByVal format As StringFormat, ByVal ranges As IEnumerable(Of CharacterRange)) As IEnumerable(Of Region)
    Dim out As New List(Of Region)(ranges.Count)

    ' Defensive copy to not side-effect caller based on shared GDI format struct
    Using fmt As StringFormat = format.Clone
        While ranges.Any
            fmt.SetMeasurableCharacterRanges(ranges.Take(32).ToArray)
            out.AddRange(g.MeasureCharacterRanges(txt, font, dest, fmt))
            ranges = ranges.Skip(32)
        End While
    End Using

    Return out
End Function