[XeTeX] Could not load both Bold and BoldItalic.

[Akira Kakuto]

> Then these fonts aren't PostScript Type 1.

PostScript Type 1 fonts can be used by XeTeX-xdvipdfmx without
tfm fonts. Of course you have to make cache for the type1 by fc-cache.
Please test
\font\f="Utopia/R"
\f This is a test.
\bye

Best,
Akira