title: What is causing Calibri to lose ClearType between 9 and 14 pt?
body: <p>What exactly is it that makes GDI+ switch to binary aliasing when using default Microsoft Office font Calibri between 9pt and 14pt with ClearTypeGridFit specified?</p>
  
  <p>It's somewhat disconcerting. How many other fonts are also affected by whatever is behind this, and at what sizes? Is there a workaround?
  (Excluding GDI, which doesn't have the same text layout features?)</p>
  
  <p><img src="https://i.stack.imgur.com/AHMEu.png" alt=""></p>
  
  <p>Here's the code I used to generate the image:</p>
  
  <pre><code>private void Form1_Paint(object sender, PaintEventArgs e)
  {
      e.Graphics.TextRenderingHint = TextRenderingHint.ClearTypeGridFit;
  
      var height = 0;
      for (var i = 1; i &lt;= 17; i++)
      {
          using (var font = new Font("Calibri", i))
          {
              var text = "ClearTypeGridFit " + i + "pt";
              e.Graphics.DrawString(text, font, SystemBrushes.ControlText, 0, height);
              height += (int)e.Graphics.MeasureString(text, font).Height;
          }
      }
  }
  </code></pre>