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Re: Metric 'font-size'

From: Christoph Päper <christoph.paeper@crissov.de>
Date: Wed, 6 Sep 2006 16:18:21 +0200
Message-Id: <DF17E8C2-4ECC-406F-8B33-B91B515B80E5@crissov.de>
To: www-style@w3.org

*Bert Bos*, 2006-08-29:
> On Tuesday 22 August 2006 21:34, Christoph Päper wrote:
>> You can use 'font-size' with millimetres and centimetres already,  
>> which is good, but I wonder whether we could add |q| as an alias  
>> for quarter an millimetre like according to that document Japanese  
>> typographers traditionally use (...) and DIN 16507-2 proposes as a  
>> modulus.
>
> It's the first time I hear a request for a 'q' and the argument  
> seems a
> bit weak...

It /is/ a bit weak, but |q| seems handier than |mm| for font sizes,  
because most common physical sizes could be expressed (approximately)  
by integer values. Otherwise you would see a lot of ".25mm", ".5mm"  
and ".75mm", if metric font sizes gained popularity. Those are of  
course not as odd as sizes in |in| would look, if we did not have an  
alias for its 72th part, |pt| (i.e, for the quoted Mac OS X series,  
rounded to three places: 0.125in, 0.139in, 0.153in, 0.167in, 0.181in,  
0.194in, 0.25in, 0.333in, 0.5in, 0.667in, 0.889in, 1in, 1.333in, 2in,  
4in), but then other preferred font sizes would have emerged.

The worst of all units in this context is of course |rad|, which  
should rather have been |pirad| to have any chance against |deg|.

Interestingly, but probably without much importance, the relationship  
of 127/90 q/pt is close to the square root of two (difference about  
0.22%). Therefore the series for preferred font sizes that Markus  
Kuhn suggests could be defined with little loss in accuracy with  
alternating units; e.g. when beginning with a maximum size of one  
decimetre (a) or a minimum of a quarter centimetre (b):

a)  400q, 200pt, 200q, 100pt,  100q,  50pt,
      50q,  25pt,  25q,  12.5pt, 12.5q, 6.25pt.

b)  160pt, 160q, 80pt, 80q, 40pt, 40q, 20pt, 20q, 10pt, 10q.

Sorry for digressing.

>> (Should 'font' be handled in the HTML4 CSS, by the way?)
>
> What do you mean? Do you want the appendix in CSS2 to say more? or  
> less?

I just wondered whether the informative default stylesheet for HTML4  
should include something like this, although |font| is deprecated:

font[size="7"]	{font-size: 3em/*?*/;}
font[size="6"]	{font-size: xx-large;}
font[size="5"]	{font-size: x-large;}
font[size="4"]	{font-size: large;}
font[size="3"]	{font-size: medium;}
font[size="2"]	{font-size: small;}
font[size="1"]	{font-size: xx-small;}
font[face]	{font-family: attr(face);}
font[color]	{color: attr(color);}
...
Received on Wednesday, 6 September 2006 14:18:36 GMT

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