I have noticed that when you save figures as jpeg using the nbagg backend you will get pixelated fonts for labels and tickmarks. It appears this has to do with giving PIL raw data with transparent regions when trying to save jpeg images. This can be avoided with setting: rcParams['nbagg.transparent'] = False.

Is this behavior desired? Perhaps there is a way we can assign default values that will be called for when you have a transparency in a figure and you are trying to save it to a file format that doesn't support transparency?

Please seehttp://stackoverflow.com/questions/33283274/pixelated-fonts-when-plot-is-saved-as-jpeg for more information.