Matplotlib default options

How may I set default options for matplotlib for a number of holoviews objects?

I have tried the below code

hv.notebook_extension(display_formats=['html', 'svg'])

fontsize = dict(labels=8, ticks=8, legend=8)
    opts.ErrorBars(elinewidth=1, show_legend=False,
                   axiswise=True, framewise=True),
    opts.Scatter(s=20, padding=0.1,
                 axiswise=True, framewise=True),
    opts.Curve(axiswise=True, framewise=True),
    opts.Overlay(axiswise=True, framewise=True),
    opts.NdOverlay(axiswise=True, framewise=True),
    opts.NdLayout(axiswise=True, framewise=True),

However when I added the fig_size above I get an error

\.conda\envs\asi\lib\site-packages\holoviews\util\ in defaults(cls, *options, **kwargs)
    285         """
    286         if kwargs and len(kwargs) != 1 and list(kwargs.keys())[0] != 'backend':
--> 287             raise Exception('opts.defaults only accepts "backend" keyword argument')
    289         cls._linemagic(cls._expand_options(merge_options_to_dict(options)), backend=kwargs.get('backend'))

Exception: opts.defaults only accepts "backend" keyword argument

Secondly, I am not sure if I have used fontsize correctly with opts objects within one call to defaults.

I believe you need to give the fig_size argument to the elements proper. Something like

hv.opts.defaults(hv.opts.Curve(axiswise=True, framewise=True, show_grid=True, fig_size=180),backend='matplotlib' )