Scale font size, useful for hidpi.

30-scale-font.conf

<?xml version='1.0'?>
<!DOCTYPE fontconfig SYSTEM 'fonts.dtd'>

<fontconfig>

  <match target="font">
    <test name="family">
      <string>Inconsolatazi4</string>
    </test>
    <edit name="pixelsize" mode="assign">
      <times>
        <name>pixelsize</name>
        <double>1.25</double>
      </times>
    </edit>
  </match>

</fontconfig>