title: Gnuplot key opaque background
body: <p>I am trying to move the legend of a plot in <code>gnuplot</code> partially outside the plot area. It seems however that the plot border is visible inside the legend, even if I set the legend property to <code>opaque</code>. </p>
  
  <p>A minimum example showing the problem:</p>
  
  <pre><code>#!/usr/bin/gnuplot -persistent
  set key at 11,1.02 box opaque
  plot sin(x)/x
  </code></pre>
  
  <p>So, I wonder how I should go about in order to make the entire interior of the key opaque white? I've thought about putting a white rectangle behind it, but it seems to be a kind of dirty solution.</p>