[pdftex] Surprising opinion about hz-type features

Reinhard Kotucha reinhard.kotucha at web.de
Sun Feb 24 01:05:24 CET 2008

Damien Wyart writes:

 > I wonder if some of you are aware of this article
 > http://home.no.net/toeng/justering/gut_hz/gutenberg_hz_english.html
 > which is also refered by 
 > http://en.wikipedia.org/wiki/Hz-program
 > If you have opinions on it, I am interested. Personnaly, I have a hard
 > time believing Zapf and Bringhurst are completely wrong ; I am almost
 > sure they have had occasions to check the B42 by themselves in museums
 > and libraries.

The point is that font expansion shouldn't be visible.  In practice
this means that expansion factors of 5% are visible, but only by TeX
users.  Expansion factors of up to 3% are usually not visible at all.

AFAIK the default value in the microtype package is 2%.  You will not
see any difference but, though the value is ridiculously small, your
paragraphs are formatted much better.

I'm convinced that it's possible to typeset Gutenberg's 42-line bible
more easily with pdftex and the quality will even be much better.

I even don't understand why people think that Gutenberg's bible is
something what Knuth calls a "masterpiece".  At the EuroTeX 2007 in
Poland we had the opportunity to browse a reprint of Gutenberg's
42-line bible.  The quality (regarding interword glue) is amazingly
high, but there is at least one place where TeX would complain about
an overfull \hbox.  Gutenberg's bible is not not as perfect as
everybody claims.

I really honor the work of Gutenberg but I'm absolutely sure that
pdftex, with font expansion and character protrusion turned on,
produces much better results.

The example text provided by Karow is a bad example.  pdftex will
never produce such bad output, unless you you set the expansion factor
to a very high value.  I suppose that this had been done by Karow in
order to demonstrate the hz-algorithm.

Of course, with expansion factors of 10% or 20%, you can easily prove
the whole concept wrong.  But it isn't.

If you have some LaTeX documents, just add the line
\usepackage{microtype} and judge yourself.  You'll get better line
breaks and less hyphenations.  But you'll never get such bad results
as presented in the article you mentioned.

Font expansion in pdftex is a great thing which improves the quality
of your documents significantly.  Just try it yourself.

There are a few interesting points in the article you mentioned,
though.  The hz-algorithm implented by URW changes the width of glyphs
but retains the width of vertical stems.  This is not a bad idea but
even if it's supported, expansion factors greater than 3% are
undesirable and you'll see no difference.

The author of the article you are talking about assumes that the
hz-algorithm is a bad thing and tries to prove his assumption, which
is definitely wrong.

The hz-algorithm implemented in pdftex works perfectly and is a big
step forward.


Reinhard Kotucha			              Phone: +49-511-4592165
Marschnerstr. 25
D-30167 Hannover	                      mailto:reinhard.kotucha at web.de
Microsoft isn't the answer. Microsoft is the question, and the answer is NO.

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