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Re: leading

From: <Jon_Bosak@novell.com>
Date: Mon, 31 Jul 1995 14:37:23 +0800
Message-Id: <9507312137.AA00384@aristotle.sjf.novell.com.SJF.Novell.COM>
To: glenn@stonehand.com, pbg@arbortext.com
Cc: Hakon.Lie@sophia.inria.fr, www-style@w3.org, jb@novell.com
[Glenn Adams:]

>     If your font size is 12pt and the distance between base lines is 14
>     pt, is leading then 2pt or 14pt?
> 
> Leading is 2pts.  The line is set 12/14 (12 on 14). Line separation is 14.

Exactly.  Here's why.

Visualize type set in metal (namely lead, Pb).  You want to increase
the space between lines; this is done by inserting a thin strip of the
same metal between the lines.  The strip is called a "lead"
(pronounced "led").  Leads come in various thicknesses: you have 1pt
leads, 2pt leads, and so on.  Thus, 12 on 14 is leaded 2 points,
because you have inserted a 2pt lead after each line.  12pt type set
solid is leaded 0 points, because no additional space has been
inserted.

[Paul Grosso:]

> Though both have at times been used, by far the more common in use
> recently--especially in the computerized typesetting world--is the
> latter, i.e., baseline-to-baseline measure, e.g., 14pt in your example.
> 
> TeX, the Output Specification (aka FOSIs), and DSSSL are among those
> that measure "leading" as baseline-to-baseline.

This is an unfortunate error, understandable from folks who have never
actually handled type, but an error nonetheless.  The parameter called
"leading" should have been named something like "line separation".  We
can't do anything about FOSI or TeX, but we should try to fix it in
DSSSL.

Jon

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Received on Monday, 31 July 1995 17:41:12 GMT

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