Marco Cimarosti wrote:

> In theory, PostScript and Unicode do not exclude each other: the former is a
> font technology (so, has to do with glyphs) and the latter is a character
> encoding (so, has to do with an abstract representation of text), so they
> have different scopes. In practice, I am afraid that PostScript did not
> (yet?) develop workable Unicode support.

This is not accurate. There are two ways PostScript fonts can avail themselves of Unicode

The first is through external mapping, in which glyphs in the font are recognised by glyph
names and mapped by an application or text engine to corresponding Unicode characters;
this works most reliably when the glyph names stored in the font correspond directly to
Unicode characters, e.g /uni0463/, although Adobe keeps a list of glyph names that their
own apps will recognise and map appropriately, e.g. /A/ for the Latin uppercase A
character. This external mapping is what has always been used for Type 1 fonts, and the
mapping is carried out by the Type 1 rasteriser (ATM or natively in the OS using Adobe
code). The limitations of this approach are that it provides no way to access glyphs that
do not directly correspond to Unicode characters, e.g. variant glyphs, and it is dependent
on external software correctly mapping from glyph names to characters.

The second, and more reliable method, is to make PostScript flavour (CFF) OpenType fonts.
These are PS Type 2 charstrings (a compressed form of the PS outline format) in an sfnt
font wrapper, i.e. the same table structure as a TrueType font. The sfnt format includes a
cmap table that directly maps from glyphs to characters and stores this mapping
internally. An OpenType font can also use advanced glyph substitution (to map variant
glyphs indirectly to characters via glyph-to-glyph lookups) and glyph positioning, e.g. to
dynamically build the kind of stacks that Peter requires. However, the latter
functionality is dependent on application support for such advanced features.

All that said, there is no good reason today why pre-press and high-end typesetting needs
to rely on PostScript fonts. Any RIP that still has trouble outputting TrueType fonts
should have been replaced long ago.

I strongly recommend Adobe InDesign for any kind of typesetting involving 'exotic'
characters and glyphs, especially the Middle East version, which includes support for
right-to-left layout and also implements more OpenType glyph positioning functionality
than the regular InDesign as well as finer manual adjustment of mark positioning. Among
many other useful features, InDesign has a glyph palette that exposes all of the glyphs in
a font, not just those that are encoded. I typeset the _Language Culture Type_ book*, and
don't think it would have been possible in any other application without making dozens of
custom fonts with hacked encodings to give me access to variant glyphs.

John Hudson

* For information about this book see


Tiro Typeworks
Vancouver, BC tiro@...

I often play against man, God says, but it is he who wants
to lose, the idiot, and it is I who want him to win.
And I succeed sometimes
In making him win.
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