noid-mklive/noid/etc/skel/.config/xfce4/xfconf/xfce-perchannel-xml/xfce4-desktop.xml

<?xml version="1.1" encoding="UTF-8"?>

<channel name="xfce4-desktop" version="1.0">
  <property name="last-settings-migration-version" type="uint" value="1"/>
  <property name="backdrop" type="empty">
    <property name="screen0" type="empty">
      <property name="monitorVirtual-1" type="empty">
        <property name="workspace0" type="empty">
          <property name="last-image" type="string" value="/usr/share/backgrounds/cat_on_book.png"/>
        </property>
      </property>
    </property>
  </property>
  <property name="last" type="empty">
    <property name="window-width" type="int" value="790"/>
    <property name="window-height" type="int" value="562"/>
  </property>
</channel>