CSS font-size-adjust paragraph example (Interactive Example)

<!doctype html>
<title>Example</title>
<style>
  body { 
    line-height: 1.2em; 
    background: #e3f3b7;
    }
  .Optima {
    font-family: optima;
    }
  .IrisUPC {
    font-family: IrisUPC;
    }
  .adjusted {
    font-size-adjust: 0.485;
    }
</style>
<article class="Optima">
  <h1>Optima (aspect ratio: 0.485)</h1>
  <p>Quis lectus nulla at volutpat diam ut. Tristique sollicitudin nibh sit amet commodo nulla facilisi. Massa tempor nec feugiat nisl pretium fusce id velit ut. Eros in cursus turpis massa tincidunt dui ut ornare. Blandit cursus risus at ultrices mi tempus imperdiet. Vitae purus faucibus ornare suspendisse sed nisi lacus sed. Proin sed libero enim sed faucibus turpis in eu.</p>
</article>

<article class="IrisUPC">
  <h1>IrisUPC (aspect ratio: 0.303)</h1>
  <p>Quis lectus nulla at volutpat diam ut. Tristique sollicitudin nibh sit amet commodo nulla facilisi. Massa tempor nec feugiat nisl pretium fusce id velit ut. Eros in cursus turpis massa tincidunt dui ut ornare. Blandit cursus risus at ultrices mi tempus imperdiet. Vitae purus faucibus ornare suspendisse sed nisi lacus sed. Proin sed libero enim sed faucibus turpis in eu.</p>
</article>

<article class="IrisUPC adjusted">
  <h1>IrisUPC (with font-size-adjust:0.485)</h1>
  <p>Quis lectus nulla at volutpat diam ut. Tristique sollicitudin nibh sit amet commodo nulla facilisi. Massa tempor nec feugiat nisl pretium fusce id velit ut. Eros in cursus turpis massa tincidunt dui ut ornare. Blandit cursus risus at ultrices mi tempus imperdiet. Vitae purus faucibus ornare suspendisse sed nisi lacus sed. Proin sed libero enim sed faucibus turpis in eu.</p>
</article>

<aside>If it doesn't work, try Firefox.</aside>