title: set IPython Notebook inline plots background not transparent
body: <p>In IPython Notebook 3, when I use the <code>Inline</code> matplotlib backend, the png figures in the browser have a transparent background.</p>
  
  <p>How do I set it to white instead?</p>
  
  <p>Minimal example:</p>
  
  <pre><code>%matplotlib inline
  import matplotlib.pyplot as plt
  plt.plot([1,2])
  </code></pre>
  
  <p>Right click and save the image, the image has a transparent background, I would like it to be white instead.</p>
  
  <p><strong>Update</strong>
  Tried to set <code>figure.facecolor</code> in <code>matplotlibrc</code> but it still displays a transparent png:</p>
  
  <pre><code>import matplotlib
  print("facecolor before:")
  print(matplotlib.rcParams["figure.facecolor"])
  %matplotlib inline
  import matplotlib.pyplot as plt
  plt.plot([1,2])
  print("facecolor after:")
  print(matplotlib.rcParams["figure.facecolor"])
  </code></pre>
  
  <p>This code gives as output:</p>
  
  <pre><code>facecolor before:
  1.0
  facecolor after:
  (1, 1, 1, 0)
  </code></pre>