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Aandi Inston wrote:
Yes. Though Acrobat never "just" substitutes another font. Acrobat uses the width table, and the other attributes of the font (e.g. is it serif, what is the stroke width), to make a substitute that is similar in design, not just spacing, to the original font.
This is then laid out using the predetermined widths.
Does kerning influence the width of a string ? It is clear that kerning influences glyph positioning, but the viewer application could (try to) compensate for that in order to keep the string width constant (by applying an extra scale factor).
Another PDF viewer might do it differently, but it is one of the sacred trusts of PDF that text is laid out with the correct spacing, whatever font gets actually used.
If the viewer application doesn't compenstate the string width for effects of kerning, we have a problem, because the viewer application has no way to know the kerning tables of the missing font on font substitution, so it doesn't know the original string width either.
This actually seems enough to satisfy a lot of users, who don't care much about the length of a serif or even what it is, so I can't go along with the "everyone must always embed" philosphy. Substitution works, and must continue to work, for the existing body of files that won't go away. Of course, in pre-press and other strict design disciplines, embedded fonts (and hence, no substitution) are a must.
I agree.
Regards,
Adriaan van Os
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