Readers Free... August 21 2008
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T here are times when even measures like kerning are not enough. Some pairs of letters just can’t fit together well enough to create nice, even letter-spacing.
You have to use special characters called ligatures.
The word comes from the Latin ligo: to bind, using the same root as the Latin words for string, bondage and imprisonment.
But this is the kind of bondage that sets you free. One of the most respected type designers in the world, Herman Zapf, told a type conference a few years ago that no-one has ever set type as well as Gutenberg did, when he set the 42-line bible in Mainz, Germany, in 1450.
“The secret of Gutenberg’s setting was that he used many more ligatures than are in common use today.”
Herr Zapf analyzed the text, and found that the secret of Gutenberg’s setting was that he used many more ligatures than are in common use today.
One problem is that there are no character codes in Unicode for more than handful of the most common ligatures – and that’s one of the reasons why Microsoft invented OpenType...
“What?”, I hear you say. “Microsoft invented OpenType?”
Well, here’s how OpenType really happened. I was there.
Microsoft had made a huge bet on TrueType, which we’d licensed from Apple.
As Windows and Office gained greater adoption all over the world, and we began to support more languages, we knew TrueType wasn’t able to handle the complex glyph substitutions and positionings needed for many Arabic and Asian languages, and it couldn’t handle less-common ligatures.
You need a layer above Unicode based on glyph indices and not character codes.
Several glyphs may all have the same Unicode value.
You need to be able to pick the right one.
In Arabic, for example, you need a different glyph for the same character code depending whether it occurs at the start, in the middle, or at the end of a word.
Unicode is no help in making that kind of contextual glyph substitution.
There are even more complex issues in other languages; stackable accents, for example, or highly complex Indic ligatures.
So we extended the TrueType font format with a new set of five tables, which we called TrueType Open, at the same time extending our major text composition engine to support them.
Peace Declared In “Font Wars”!
When Adobe’s type folks learned what we’d done, they said they’d like to use the same tables in their Type1 and CFF font formats.
There was still a lot of bad feeling between Microsoft and Adobe at the time, which went back to the bitter days of the TrueType-versus-PostScript “Font Wars”.
But Bill McCoy of Adobe and I both felt it was time to put all that behind us. So, with my friend and colleague Greg Hitchcock, we came up with a new format that allowed either TrueType or PostScript outline data in a font, combined with the new tables. I suggested the name OpenType. And peace broke out!
It’s ironic that Adobe then did a much better job than we did of integrating OpenType into all of its applications.
However, I’m determined to keep up the pressure to make OpenType work on the Web. We need it, for the screen to take over as the publishing medium of choice.