<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>At-Page Size</title>
<style>
  body {
    margin: 0;
  }
  .rect {
      /* An outlined rect that is 1inch smaller in each dimension,
         to help visualize if the output page is the right size or not: */
      width: calc(4in - 1in - 4px);
      height: calc(12in - 1in - 4px);
      border: 2px solid black;
  }
  @page {
    size: 4in 12in;
    margin: 0.5in;
  }
</style>
</head>
<body>
  <div class="rect">
    <h3>Expectation:</h3>
    If you print-preview using the "Save to PDF" page target, you should see an
    4in-by-12in-size sheet of paper by default, just 1 inch wider (0.5in margins) than the
    black-outlined box.
  </div>
</body>
</html>
