title: Inconsistent font size for scientific notation in axis
body: <p>I'm trying to make a plot for which the x axis will show in scientific notation. The way I found how to do so is to use the <code>ticklabel_format</code> function. Unfortunately this does not respect the font size I assign to the numbers shown in the axis, see image below:</p>
  
  <p><img src="https://i.stack.imgur.com/waP5T.png" alt="enter image description here"></p>
  
  <p>The <code>1e-12</code> and <code>1e4</code> are displayed in a different font size even though I set equal label sizes.</p>
  
  <p>How could I fix this? (A <code>MWE</code> is below)</p>
  
  <pre><code>import matplotlib.pyplot as plt
  import numpy as np
  
  t = np.arange(0.0, 10000.0, 10.)
  s = np.sin(np.pi*t)*np.exp(-t*0.0001)
  
  fig, ax = plt.subplots()
  
  ax.tick_params(axis='both', which='major', labelsize=7)
  plt.ticklabel_format(style='sci', axis='x', scilimits=(0,0), labelsize=7)
  plt.plot(t,s)
  
  plt.show()
  </code></pre>