title: How to generate a transparent canvas using html2canvas
body: <p>this seems like it should be a simple thing but it's crazily difficult.</p>
  
  <p>I simply have a div DOM element with some text inside.</p>
  
  <p>I'm calling the html2canvas method on it and it's working find.</p>
  
  <p>The only problem, the canvas has a white background!</p>
  
  <p>I tried:</p>
  
  <ul>
  <li>Setting the background property on the options object to null</li>
  <li>Explicitly changing the CSS background property to transparent on the canvas and the DOM element that it was being generated from</li>
  </ul>
  
  <p>Unfortunately nothing seems to work.</p>
  
  <p>Hopefully there is an elegant solution but a quick hack is okay.</p>