<fontconfig>

  <alias>

    <family>[genericname]</family>

    <prefer>

      <family>[fontname]</family>

    </prefer>

  </alias>

  <alias>

    <family>[fontname]</family>

    <default>

      <family>[genericname]</family>

    </default>

  </alias>

  <match target="font">

    <test name="family" mode="eq">

      <string>[fontname]</string>

    </test>

    <edit name="matrix" mode="assign">

      <times>

        <name>matrix</name>

        <matrix>

          <double>[factor]</double>

          <double>0</double>

          <double>0</double>

          <double>[factor]</double>

        </matrix>

      </times>

    </edit>

  </match>

</fontconfig>