W3C home > Mailing lists > Public > www-style@w3.org > January 2000

Re: ascender, descender, cap-height and x-height

From: Prof. Erik Spiekermann <erik@metadesign.com>
Date: Wed, 26 Jan 2000 04:07:33 -0500 (EST)
Message-ID: <B4B477DB.B76%erik@metadesign.com>
To: Jelle Bosma <jelleb@euronet.nl>, Erik van der Poel <erik@netscape.com>, <www-font@w3.org>
on 26.01.2000 09:13, Jelle Bosma wrote:

> 
> -----Oorspronkelijk bericht-----
> Van: Erik van der Poel <erik@netscape.com>
> Aan: www-font@w3.org <www-font@w3.org>
> Datum: dinsdag 25 januari 2000 23:11
> Onderwerp: Re: ascender, descender, cap-height and x-height
> 
> 
>> All,
>> So, if the actual glyphs have such a loose relationship with the em
>> square, and font size is defined in terms of em square, then
>> font-size-adjust becomes ill-defined too, since aspect is defined in
>> terms of font size (and x-height).
>> 
>> I think the font size should be the sum of the "nominal" ascender and
>> the nominal descender for fonts with upper and lower case letters, and
>> some other nominal value for other fonts. That's why I'd like to know
>> whether I can reliably determine ascender, descender and x-height, and
>> how to do that.
>> 
> 
> 
> It is the type designer who decides on how large the font
> is in the EM square. There are no rules. In TrueType
> (and OpenType) you can get some measurements such
> as the Typographic ascend and descend as explained by Greg.
> These values are in the OS/2 table of the font.
> In Monotype fonts these are set to top f and bottom g
> for the font family. Whether fonts of other foundries
> contain reliable values I am not sure. Many foundries didn't
> bother much about these things until recently.
> 
> Jelle Bosma
> Agfa Monotype
> 
> 
> 
BTW: AFM files produced by Fontographer et al also include these
measurements.

--

= 8-) 

| Prof. Erik Spiekermann | erik@metadesign.com |

| MetaDesign | Berlin | London | San Francisco |
| Europe +49-172-3131711 | USA +1-415-203 7130 |

|    STRESSED spelled backwards is DESSERTS.   |
Received on Wednesday, 26 January 2000 12:31:25 GMT

This archive was generated by hypermail 2.2.0+W3C-0.50 : Monday, 27 April 2009 13:54:03 GMT