gtk2/testsuite/css/style/font.css

box {
  font: 10px "Comic Sans";
}

#label1 {
  font-size: smaller;
}

#label2 {
  font: 10pt Cantarell, sans-serif;
}

#label3 {
  font: bold italic 80% monospace;
}

#label4 {
  font: expanded oblique xx-small serif;
}

#label5 {
  font: 20mm '21st Century';
}