Bug report

The PDF logo doesn't look quite right, viewed in Adobe Acrobat, Preview, and Google Chrome (on macOS). If you look closely at the center, there are some extra features there that don't show up in, for instance, the svg.

https://github.com/matplotlib/matplotlib/blob/master/lib/matplotlib/mpl-data/images/matplotlib.pdf

Maybe somebody should track down why the render of the PDF glitched? At least replace it with one that isn't glitchy?