The Unicode range of the displayed text in PDF documents must be covered by the embedded font.
Unfortunately, at present there is no native outline font that can display all Unicode characters. The one exception is GNU Unifont, which does support the full 65,536 Unicode code point range. However, the glyphs originate from a bitmap of 16 pixels high and either 8 or 16 pixels wide, which gives the font a coarser look.
SavaPage contains internal fonts covering specific Unicode Scripts. These fonts
can be selected to customize PDF output to the content locale.
The default font for PDF output is DejaVu Sans, which supports a broad set of Unicode scripts:
Latin (including European and African alphabets, IPA, ...)
Greek (including polytonic)
Cyrillic
Armenian
Georgian
Hebrew
Arabic
N'ko
Lao
Canadian Aboriginal Syllabics
Ogham
Tifinagh
Lisu
Next to that, DejaVu also contains a lot of mathematical and other symbols, arrows, braille patterns, etc.
Coverage of the default font can be seen in DejaVuSans.pdf.
Support for Chinese, Japanese and Korean (CJK) is provided by the Droid Sans "fallback"
font. This font contains over 43,000 glyphs and includes support for
Simplified Chinese (GB2312), Traditional Chinese (Big 5), Japanese (JIS 0208)
and Korean (KSC 5601). The font uses the Simplified Chinese ideographs for
shared Unicode code points.
Coverage of the CJK font can be seen in DroidSansFallbackFull.pdf.
GNU Unifont is a Unicode font with a glyph for every visible Unicode Basic Multilingual Plane code point. The Unicode Basic Multilingual Plane covers the first 65,536 (or 2^16) Unicode code points. GNU Unifont originates from a bitmap font with glyphs of 16 pixels high and either 8 or 16 pixels wide. Therefore it has a coarser look than native outline fonts.