Before you can use a new font, you must locate a font file that contains the diagrams of the font's characters. Font files come in various formats, not all of which will work with a given XSL-FO processor. Typical font file formats include TrueType and PostScript Type 1. If you have a Windows system, you can find several TrueType fonts under \WINDOWS\FONTS with a .ttf filename extension.

It is generally best to embed extra fonts in the generated PDF file, since the new fonts are unlikely to be resident and available on a given printer. With embedded fonts, the character diagrams are included in your PDF file, which makes your document portable. But the font file you use must permit the font to be embedded.

FOP will accept PostScript Type 1 and TrueType fonts. There are some restrictions and several options for using fonts in FOP. See http://xml.apache.org/fop/fonts.html for more details about configuring fonts in FOP. The following procedure configures a Garamond TrueType font, including its bold and italic variations.

The XEP documentation provides details for configuring XEP to use other fonts. The simplest case is to install the font directly in the afm directory in the XEP installation area on your system. Then you can just edit the xep.xml file that is in the XEP installation (or etc/fonts.xml prior to version 4). For example, these lines add the TrueType Palatino fonts to a version 4 installation.

<font-family name="Palatino" embed="true" 
             ligatures="&#xFB00; &#xFB01; &#xFB02; &#xFB03; &#xFB04;">
  <font>
    <font-data ttf="pala.ttf"/>
  </font>
 
  <font style="italic">
    <font-data ttf="palai.ttf"/>
  </font>
 
  <font weight="bold">
    <font-data ttf="palab.ttf"/>
  </font>
 
  <font weight="bold" style="italic">
    <font-data ttf="palabi.ttf"/>
  </font>

</font-family>

The pathname to the .ttf file is taken to be relative to the afm directory. Placing the font files in that directory simplifies the configuration. Or use a font-group wrapper to specify a path.

XEP uses the style and weight attributes to switch to bold and italic for inline font changes.

To add a new font to your stylesheet, you may be able to do so with a stylesheet parameter. Otherwise, you will need to write a customization. The FO stylesheet provides a few parameters to specify font family names. These include:

If you want to change any of these, then you just need to set the corresponding parameter in a customization layer or on the command line. The value must match the name in the font configuration file for the FO processor. For example, to set the body font to Garamond, add this line to your customization layer:

<xsl:param name="body.font.family">Garamond</xsl:param>

When processed with the stylesheet, the FO output includes the following:

<fo:root  font-family="Garamond" ... >

If you then process the FO output with FOP or XEP as configured above, your PDF output should use Garamond for the body font. If you also configured the bold and italic font files, then those should automatically be used when needed.

The three stylesheet font parameters may not meet your needs if you need finer control. For example, the title.font.family applies to all titles, but you may want your book and chapter titles in one font, and your section titles in a different font. The section title font is controlled by a couple of attribute-sets. See the section “Section titles” for a description of those attribute sets. In a customization layer, you only need to specify the new font in the appropriate attribute-set. This example sets the font for all levels of section titles:

<xsl:attribute-set name="section.title.properties">
  <xsl:attribute name="font-family">Garamond</xsl:attribute>
  <xsl:attribute name="font-weight">bold</xsl:attribute>
</xsl:attribute-set>

These properties will be merged with the attribute-set of the same name in the stylesheet, overriding the default font settings while leaving the other properties in effect.

If the element for which you want to change the font does not have an attribute-set in the stylesheet, you will have to customize the template that formats the element. For an example of customizing an element's font, see the section “Line annotations”.