diff --git a/mne/datasets/utils.py b/mne/datasets/utils.py
index 5e74c10e912..2304861d871 100644
--- a/mne/datasets/utils.py
+++ b/mne/datasets/utils.py
@@ -239,7 +239,7 @@ def _data_path(path=None, force_update=False, update_path=True, download=True,
     path = _get_path(path, key, name)
     # To update the testing or misc dataset, push commits, then make a new
     # release on GitHub. Then update the "releases" variable:
-    releases = dict(testing='0.97', misc='0.6')
+    releases = dict(testing='0.98', misc='0.6')
     # And also update the "md5_hashes['testing']" variable below.
 
     # To update any other dataset, update the data archive itself (upload
@@ -326,7 +326,7 @@ def _data_path(path=None, force_update=False, update_path=True, download=True,
         sample='12b75d1cb7df9dfb4ad73ed82f61094f',
         somato='ea825966c0a1e9b2f84e3826c5500161',
         spm='9f43f67150e3b694b523a21eb929ea75',
-        testing='603c3f087c4dbf151c729341342095c7',
+        testing='7c1dcfacaac7759aa40bfb800c791d85',
         multimodal='26ec847ae9ab80f58f204d09e2c08367',
         fnirs_motor='c4935d19ddab35422a69f3326a01fef8',
         opm='370ad1dcfd5c47e029e692c85358a374',
diff --git a/mne/source_estimate.py b/mne/source_estimate.py
index 9cae3eab622..11ffbc0ad3e 100644
--- a/mne/source_estimate.py
+++ b/mne/source_estimate.py
@@ -615,12 +615,12 @@ def plot(self, subject=None, surface='inflated', hemi='lh',
              colormap='auto', time_label='auto', smoothing_steps=10,
              transparent=True, alpha=1.0, time_viewer='auto',
              subjects_dir=None,
-             figure=None, views='lat', colorbar=True, clim='auto',
+             figure=None, views='auto', colorbar=True, clim='auto',
              cortex="classic", size=800, background="black",
              foreground=None, initial_time=None, time_unit='s',
              backend='auto', spacing='oct6', title=None, show_traces='auto',
              src=None, volume_options=1., view_layout='vertical',
-             verbose=None):
+             add_data_kwargs=None, verbose=None):
         brain = plot_source_estimates(
             self, subject, surface=surface, hemi=hemi, colormap=colormap,
             time_label=time_label, smoothing_steps=smoothing_steps,
@@ -631,7 +631,7 @@ def plot(self, subject=None, surface='inflated', hemi='lh',
             initial_time=initial_time, time_unit=time_unit, backend=backend,
             spacing=spacing, title=title, show_traces=show_traces,
             src=src, volume_options=volume_options, view_layout=view_layout,
-            verbose=verbose)
+            add_data_kwargs=add_data_kwargs, verbose=verbose)
         return brain
 
     @property
@@ -1904,11 +1904,13 @@ def project(self, directions, src=None, use_cps=True):
     def plot(self, subject=None, hemi='lh', colormap='hot', time_label='auto',
              smoothing_steps=10, transparent=True, brain_alpha=0.4,
              overlay_alpha=None, vector_alpha=1.0, scale_factor=None,
-             time_viewer='auto', subjects_dir=None, figure=None, views='lat',
+             time_viewer='auto', subjects_dir=None, figure=None,
+             views='lateral',
              colorbar=True, clim='auto', cortex='classic', size=800,
              background='black', foreground=None, initial_time=None,
              time_unit='s', show_traces='auto', src=None, volume_options=1.,
-             view_layout='vertical', verbose=None):  # noqa: D102
+             view_layout='vertical', add_data_kwargs=None,
+             verbose=None):  # noqa: D102
         return plot_vector_source_estimates(
             self, subject=subject, hemi=hemi, colormap=colormap,
             time_label=time_label, smoothing_steps=smoothing_steps,
@@ -1920,7 +1922,8 @@ def plot(self, subject=None, hemi='lh', colormap='hot', time_label='auto',
             background=background, foreground=foreground,
             initial_time=initial_time, time_unit=time_unit,
             show_traces=show_traces, src=src, volume_options=volume_options,
-            view_layout=view_layout, verbose=verbose)
+            view_layout=view_layout, add_data_kwargs=add_data_kwargs,
+            verbose=verbose)
 
 
 class _BaseVolSourceEstimate(_BaseSourceEstimate):
@@ -1938,7 +1941,7 @@ def plot_3d(self, subject=None, surface='white', hemi='both',
                 foreground=None, initial_time=None, time_unit='s',
                 backend='auto', spacing='oct6', title=None, show_traces='auto',
                 src=None, volume_options=1., view_layout='vertical',
-                verbose=None):
+                add_data_kwargs=None, verbose=None):
         return super().plot(
             subject=subject, surface=surface, hemi=hemi, colormap=colormap,
             time_label=time_label, smoothing_steps=smoothing_steps,
@@ -1949,7 +1952,8 @@ def plot_3d(self, subject=None, surface='white', hemi='both',
             foreground=foreground, initial_time=initial_time,
             time_unit=time_unit, backend=backend, spacing=spacing, title=title,
             show_traces=show_traces, src=src, volume_options=volume_options,
-            view_layout=view_layout, verbose=verbose)
+            view_layout=view_layout, add_data_kwargs=add_data_kwargs,
+            verbose=verbose)
 
     @copy_function_doc_to_method_doc(plot_volume_source_estimates)
     def plot(self, src, subject=None, subjects_dir=None, mode='stat_map',
@@ -2267,7 +2271,7 @@ def plot_3d(self, subject=None, hemi='both', colormap='hot',
                 background='black', foreground=None, initial_time=None,
                 time_unit='s', show_traces='auto', src=None,
                 volume_options=1., view_layout='vertical',
-                verbose=None):  # noqa: D102
+                add_data_kwargs=None, verbose=None):  # noqa: D102
         return _BaseVectorSourceEstimate.plot(
             self, subject=subject, hemi=hemi, colormap=colormap,
             time_label=time_label, smoothing_steps=smoothing_steps,
@@ -2279,7 +2283,8 @@ def plot_3d(self, subject=None, hemi='both', colormap='hot',
             background=background, foreground=foreground,
             initial_time=initial_time, time_unit=time_unit,
             show_traces=show_traces, src=src, volume_options=volume_options,
-            view_layout=view_layout, verbose=verbose)
+            view_layout=view_layout, add_data_kwargs=add_data_kwargs,
+            verbose=verbose)
 
 
 @fill_doc
diff --git a/mne/surface.py b/mne/surface.py
index a7a72b5c166..06d7d0d0327 100644
--- a/mne/surface.py
+++ b/mne/surface.py
@@ -764,6 +764,53 @@ def _read_wavefront_obj(fname):
     return np.array(coords), np.array(faces)
 
 
+def _read_patch(fname):
+    """Load a FreeSurfer binary patch file.
+
+    Parameters
+    ----------
+    fname : str
+        The filename.
+
+    Returns
+    -------
+    rrs : ndarray, shape (n_vertices, 3)
+        The points.
+    tris : ndarray, shape (n_tris, 3)
+        The patches. Not all vertices will be present.
+    """
+    # This is adapted from PySurfer PR #269, Bruce Fischl's read_patch.m,
+    # and PyCortex (BSD)
+    patch = dict()
+    with open(fname, 'r') as fid:
+        ver = np.fromfile(fid, dtype='>i4', count=1)[0]
+        if ver != -1:
+            raise RuntimeError(f'incorrect version # {ver} (not -1) found')
+        npts = np.fromfile(fid, dtype='>i4', count=1)[0]
+        dtype = np.dtype(
+            [('vertno', '>i4'), ('x', '>f'), ('y', '>f'), ('z', '>f')])
+        recs = np.fromfile(fid, dtype=dtype, count=npts)
+    # numpy to dict
+    patch = {key: recs[key] for key in dtype.fields.keys()}
+    patch['vertno'] -= 1
+
+    # read surrogate surface
+    rrs, tris = read_surface(
+        op.join(op.dirname(fname), op.basename(fname)[:3] + 'sphere'))
+    orig_tris = tris
+    is_vert = patch['vertno'] > 0  # negative are edges, ignored for now
+    verts = patch['vertno'][is_vert]
+
+    # eliminate invalid tris and zero out unused rrs
+    mask = np.zeros((len(rrs),), dtype=bool)
+    mask[verts] = True
+    rrs[~mask] = 0.
+    tris = tris[mask[tris].all(1)]
+    for ii, key in enumerate(['x', 'y', 'z']):
+        rrs[verts, ii] = patch[key][is_vert]
+    return rrs, tris, orig_tris
+
+
 ##############################################################################
 # SURFACE CREATION
 
diff --git a/mne/tests/test_surface.py b/mne/tests/test_surface.py
index fa25c98b033..0ada7494682 100644
--- a/mne/tests/test_surface.py
+++ b/mne/tests/test_surface.py
@@ -13,7 +13,7 @@
                  dig_mri_distances)
 from mne.surface import (read_morph_map, _compute_nearest, _tessellate_sphere,
                          fast_cross_3d, get_head_surf, read_curvature,
-                         get_meg_helmet_surf, _normal_orth)
+                         get_meg_helmet_surf, _normal_orth, _read_patch)
 from mne.utils import (_TempDir, requires_vtk, catch_logging,
                        run_tests_if_main, object_diff, requires_freesurfer)
 from mne.io import read_info
@@ -183,6 +183,12 @@ def test_io_surface():
         assert_array_equal(pts, c_pts)
         assert_array_equal(tri, c_tri)
 
+    # reading patches (just a smoke test, let the flatmap viz tests be more
+    # complete)
+    fname_patch = op.join(
+        data_path, 'subjects', 'fsaverage', 'surf', 'rh.cortex.patch.flat')
+    _read_patch(fname_patch)
+
 
 @testing.requires_testing_data
 def test_read_curv():
diff --git a/mne/utils/docs.py b/mne/utils/docs.py
index 3eacb38b566..265a575aa8b 100644
--- a/mne/utils/docs.py
+++ b/mne/utils/docs.py
@@ -1058,6 +1058,21 @@
     Can be "vertical" (default) or "horizontal". When using "horizontal" mode,
     the PyVista backend must be used and hemi cannot be "split".
 """
+docdict['add_data_kwargs'] = """
+add_data_kwargs : dict | None
+    Additional arguments to brain.add_data (e.g.,
+    ``dict(time_label_size=10)``).
+"""
+docdict['views'] = """
+views : str | list
+    View to use. Can be any of::
+
+        ['lateral', 'medial', 'rostral', 'caudal', 'dorsal', 'ventral',
+         'frontal', 'parietal', 'axial', 'sagittal', 'coronal']
+
+    Three letter abbreviations (e.g., ``'lat'``) are also supported.
+    Using multiple views (list) is not supported for mpl backend.
+"""
 
 # STC label time course
 docdict['eltc_labels'] = """
diff --git a/mne/viz/_3d.py b/mne/viz/_3d.py
index 4c89132019d..a7890f5d163 100644
--- a/mne/viz/_3d.py
+++ b/mne/viz/_3d.py
@@ -1426,6 +1426,7 @@ def _plot_mpl_stc(stc, subject=None, surface='inflated', hemi='lh',
                  'par': {'elev': 30, 'azim': -60}}
     time_viewer = False if time_viewer == 'auto' else time_viewer
     kwargs = dict(lh=lh_kwargs, rh=rh_kwargs)
+    views = 'lat' if views == 'auto' else views
     _check_option('views', views, sorted(lh_kwargs.keys()))
     mapdata = _process_clim(clim, colormap, transparent, stc.data)
     _separate_map(mapdata)
@@ -1582,13 +1583,13 @@ def plot_source_estimates(stc, subject=None, surface='inflated', hemi='lh',
                           colormap='auto', time_label='auto',
                           smoothing_steps=10, transparent=True, alpha=1.0,
                           time_viewer='auto', subjects_dir=None, figure=None,
-                          views='lat', colorbar=True, clim='auto',
+                          views='auto', colorbar=True, clim='auto',
                           cortex="classic", size=800, background="black",
                           foreground=None, initial_time=None,
                           time_unit='s', backend='auto', spacing='oct6',
                           title=None, show_traces='auto',
                           src=None, volume_options=1., view_layout='vertical',
-                          verbose=None):
+                          add_data_kwargs=None, verbose=None):
     """Plot SourceEstimate.
 
     Parameters
@@ -1629,10 +1630,14 @@ def plot_source_estimates(stc, subject=None, surface='inflated', hemi='lh',
         length. If int is provided it will be used to identify the Mayavi
         figure by it's id or create a new figure with the given id. If an
         instance of matplotlib figure, mpl backend is used for plotting.
-    views : str | list
-        View to use. See `surfer.Brain`. Supported views: ['lat', 'med', 'ros',
-        'cau', 'dor' 'ven', 'fro', 'par']. Using multiple views is not
-        supported for mpl backend.
+    %(views)s
+
+        When plotting a standard SourceEstimate (not volume, mixed, or vector)
+        and using the PyVista backend, ``views='flat'`` is also supported to
+        plot cortex as a flatmap.
+
+        .. versionchanged:: 0.21.0
+           Support for flatmaps.
     colorbar : bool
         If True, display colorbar on scene.
     %(clim)s
@@ -1676,6 +1681,7 @@ def plot_source_estimates(stc, subject=None, surface='inflated', hemi='lh',
         .. versionadded:: 0.17.0
     %(show_traces)s
     %(src_volume_options_layout)s
+    %(add_data_kwargs)s
     %(verbose)s
 
     Returns
@@ -1683,6 +1689,17 @@ def plot_source_estimates(stc, subject=None, surface='inflated', hemi='lh',
     figure : instance of surfer.Brain | matplotlib.figure.Figure
         An instance of :class:`surfer.Brain` from PySurfer or
         matplotlib figure.
+
+    Notes
+    -----
+    Flatmaps are available by default for ``fsaverage`` but not for other
+    subjects reconstructed by FreeSurfer. We recommend using
+    :func:`mne.compute_source_morph` to morph source estimates to ``fsaverage``
+    for flatmap plotting. If you want to construct your own flatmap for a given
+    subject, these links might help:
+
+    - https://surfer.nmr.mgh.harvard.edu/fswiki/FreeSurferOccipitalFlattenedPatch
+    - https://openwetware.org/wiki/Beauchamp:FreeSurfer
     """  # noqa: E501
     from .backends.renderer import _get_3d_backend, set_3d_backend
     from ..source_estimate import _BaseSourceEstimate
@@ -1716,7 +1733,7 @@ def plot_source_estimates(stc, subject=None, surface='inflated', hemi='lh',
         stc, overlay_alpha=alpha, brain_alpha=alpha, vector_alpha=alpha,
         cortex=cortex, foreground=foreground, size=size, scale_factor=None,
         show_traces=show_traces, src=src, volume_options=volume_options,
-        view_layout=view_layout, **kwargs)
+        view_layout=view_layout, add_data_kwargs=add_data_kwargs, **kwargs)
 
 
 def _plot_stc(stc, subject, surface, hemi, colormap, time_label,
@@ -1724,7 +1741,7 @@ def _plot_stc(stc, subject, surface, hemi, colormap, time_label,
               time_unit, background, time_viewer, colorbar, transparent,
               brain_alpha, overlay_alpha, vector_alpha, cortex, foreground,
               size, scale_factor, show_traces, src, volume_options,
-              view_layout):
+              view_layout, add_data_kwargs):
     from .backends.renderer import _get_3d_backend
     vec = stc._data_ndim == 3
     subjects_dir = get_subjects_dir(subjects_dir=subjects_dir,
@@ -1739,7 +1756,7 @@ def _plot_stc(stc, subject, surface, hemi, colormap, time_label,
         _require_version('surfer', 'stc.plot', '0.9')
     else:  # PyVista
         from ._brain import _Brain as Brain
-
+    views = _check_views(surface, views, hemi, stc, backend)
     _check_option('hemi', hemi, ['lh', 'rh', 'split', 'both'])
     _check_option('view_layout', view_layout, ('vertical', 'horizontal'))
     time_label, times = _handle_time(time_label, time_unit, stc.times)
@@ -1842,6 +1859,7 @@ def _plot_stc(stc, subject, surface, hemi, colormap, time_label,
             kwargs["clim"] = clim
             kwargs["volume_options"] = volume_options
             kwargs["src"] = src_vol
+        kwargs.update({} if add_data_kwargs is None else add_data_kwargs)
         with warnings.catch_warnings(record=True):  # traits warnings
             brain.add_data(**kwargs)
         brain.scale_data_colormap(fmin=scale_pts[0], fmid=scale_pts[1],
@@ -2346,19 +2364,44 @@ def _check_pysurfer_antialias(Brain):
     return kwargs
 
 
+def _check_views(surf, views, hemi, stc=None, backend=None):
+    from ..source_estimate import SourceEstimate
+    _validate_type(views, (list, tuple, str), 'views')
+    views = [views] if isinstance(views, str) else list(views)
+    if surf == 'flat':
+        _check_option('views', views, (['auto'], ['flat']))
+        views = ['flat']
+    elif len(views) == 1 and views[0] == 'auto':
+        views = ['lateral']
+    if views == ['flat']:
+        if stc is not None:
+            _validate_type(stc, SourceEstimate, 'stc',
+                           'SourceEstimate when a flatmap is used')
+        if backend is not None:
+            if backend != 'pyvista':
+                raise RuntimeError('The PyVista 3D backend must be used to '
+                                   'plot a flatmap')
+    if (views == ['flat']) ^ (surf == 'flat'):  # exactly only one of the two
+        raise ValueError('surface="flat" must be used with views="flat", got '
+                         f'surface={repr(surf)} and views={repr(views)}')
+    return views
+
+
 @verbose
 def plot_vector_source_estimates(stc, subject=None, hemi='lh', colormap='hot',
                                  time_label='auto', smoothing_steps=10,
                                  transparent=None, brain_alpha=0.4,
                                  overlay_alpha=None, vector_alpha=1.0,
                                  scale_factor=None, time_viewer='auto',
-                                 subjects_dir=None, figure=None, views='lat',
+                                 subjects_dir=None, figure=None,
+                                 views='lateral',
                                  colorbar=True, clim='auto', cortex='classic',
                                  size=800, background='black',
                                  foreground=None, initial_time=None,
                                  time_unit='s', show_traces='auto',
                                  src=None, volume_options=1.,
-                                 view_layout='vertical', verbose=None):
+                                 view_layout='vertical',
+                                 add_data_kwargs=None, verbose=None):
     """Plot VectorSourceEstimate with PySurfer.
 
     A "glass brain" is drawn and all dipoles defined in the source estimate
@@ -2406,8 +2449,7 @@ def plot_vector_source_estimates(stc, subject=None, hemi='lh', colormap='hot',
         split view is requested, this must be a list of the appropriate
         length. If int is provided it will be used to identify the Mayavi
         figure by it's id or create a new figure with the given id.
-    views : str | list
-        View to use. See `surfer.Brain`.
+    %(views)s
     colorbar : bool
         If True, display colorbar on scene.
     %(clim_onesided)s
@@ -2433,6 +2475,7 @@ def plot_vector_source_estimates(stc, subject=None, hemi='lh', colormap='hot',
         milliseconds ("ms").
     %(show_traces)s
     %(src_volume_options_layout)s
+    %(add_data_kwargs)s
     %(verbose)s
 
     Returns
@@ -2459,7 +2502,8 @@ def plot_vector_source_estimates(stc, subject=None, hemi='lh', colormap='hot',
         brain_alpha=brain_alpha, overlay_alpha=overlay_alpha,
         vector_alpha=vector_alpha, cortex=cortex, foreground=foreground,
         size=size, scale_factor=scale_factor, show_traces=show_traces,
-        src=src, volume_options=volume_options, view_layout=view_layout)
+        src=src, volume_options=volume_options, view_layout=view_layout,
+        add_data_kwargs=add_data_kwargs)
 
 
 @verbose
diff --git a/mne/viz/_brain/_brain.py b/mne/viz/_brain/_brain.py
index c0fd1fd061d..ac2c4bb8341 100644
--- a/mne/viz/_brain/_brain.py
+++ b/mne/viz/_brain/_brain.py
@@ -17,7 +17,7 @@
 from .surface import Surface
 from .view import views_dicts
 
-from .._3d import _process_clim, _handle_time
+from .._3d import _process_clim, _handle_time, _check_views
 
 from ...defaults import _handle_default
 from ...surface import mesh_edges
@@ -154,13 +154,15 @@ class _Brain(object):
        +---------------------------+--------------+-----------------------+
        | view_layout               |              | ✓                     |
        +---------------------------+--------------+-----------------------+
+       | flatmaps                  |              | ✓                     |
+       +---------------------------+--------------+-----------------------+
 
     """
 
     def __init__(self, subject_id, hemi, surf, title=None,
                  cortex="classic", alpha=1.0, size=800, background="black",
                  foreground=None, figure=None, subjects_dir=None,
-                 views=['lateral'], offset=True, show_toolbar=False,
+                 views='auto', offset=True, show_toolbar=False,
                  offscreen=False, interaction='trackball', units='mm',
                  view_layout='vertical', show=True):
         from ..backends.renderer import backend, _get_renderer, _get_3d_backend
@@ -196,6 +198,7 @@ def __init__(self, subject_id, hemi, surf, title=None,
 
         if isinstance(views, str):
             views = [views]
+        views = _check_views(surf, views, hemi)
         col_dict = dict(lh=1, rh=1, both=1, split=2)
         shape = (len(views), col_dict[hemi])
         if self._view_layout == 'horizontal':
@@ -291,6 +294,10 @@ def __init__(self, subject_id, hemi, surf, title=None,
         self._closed = False
         if show:
             self._renderer.show()
+        # update the views once the geometry is all set
+        for h in self._hemis:
+            for ri, ci, v in self._iter_views(h):
+                self.show_view(v, row=ri, col=ci, hemi=h)
 
     @property
     def interaction(self):
@@ -326,7 +333,8 @@ def add_data(self, array, fmin=None, fmid=None, fmax=None,
                  time_label="auto", colorbar=True,
                  hemi=None, remove_existing=None, time_label_size=None,
                  initial_time=None, scale_factor=None, vector_alpha=None,
-                 clim=None, src=None, volume_options=0.4, verbose=None):
+                 clim=None, src=None, volume_options=0.4, colorbar_kwargs=None,
+                 verbose=None):
         """Display data from a numpy array on the surface or volume.
 
         This provides a similar interface to
@@ -384,7 +392,8 @@ def add_data(self, array, fmin=None, fmid=None, fmax=None,
             time points in the data array (if data is 2D or 3D)
         %(time_label)s
         colorbar : bool
-            whether to add a colorbar to the figure
+            whether to add a colorbar to the figure. Can also be a tuple
+            to give the (row, col) index of where to put the colorbar.
         hemi : str | None
             If None, it is assumed to belong to the hemisphere being
             shown. If two hemispheres are being shown, an error will
@@ -409,6 +418,9 @@ def add_data(self, array, fmin=None, fmid=None, fmax=None,
         clim : dict
             Original clim arguments.
         %(src_volume_options_layout)s
+        colorbar_kwargs : dict | None
+            Options to pass to :meth:`pyvista.BasePlotter.add_scalar_bar`
+            (e.g., ``dict(title_font_size=10)``).
         %(verbose)s
 
         Notes
@@ -430,7 +442,12 @@ def add_data(self, array, fmin=None, fmid=None, fmax=None,
         # those parameters are not supported yet, only None is allowed
         _check_option('thresh', thresh, [None])
         _check_option('remove_existing', remove_existing, [None])
-        _check_option('time_label_size', time_label_size, [None])
+        _validate_type(time_label_size, (None, 'numeric'), 'time_label_size')
+        if time_label_size is not None:
+            time_label_size = float(time_label_size)
+            if time_label_size < 0:
+                raise ValueError('time_label_size must be positive, got '
+                                 f'{time_label_size}')
 
         hemi = self._check_hemi(hemi, extras=['vol'])
         array = np.asarray(array)
@@ -479,6 +496,8 @@ def add_data(self, array, fmin=None, fmid=None, fmax=None,
         fmin, fmid, fmax = _update_limits(
             fmin, fmid, fmax, center, array
         )
+        if colormap == 'auto':
+            colormap = 'mne' if center is not None else 'hot'
 
         if smoothing_steps is None:
             smoothing_steps = 7
@@ -538,10 +557,13 @@ def add_data(self, array, fmin=None, fmid=None, fmax=None,
         self.set_data_smoothing(self._data['smoothing_steps'])
 
         # 3) add the other actors
+        if colorbar is True:
+            # botto left by default
+            colorbar = (self._subplot_shape[0] - 1, 0)
         for ri, ci, v in self._iter_views(hemi):
             self._renderer.subplot(ri, ci)
             # Add the time label to the bottommost view
-            do = (ri == self._subplot_shape[0] - 1)
+            do = (ri, ci) == colorbar
             if not self._time_label_added and time_label is not None and do:
                 time_actor = self._renderer.text2d(
                     x_window=0.95, y_window=y_txt,
@@ -553,9 +575,10 @@ def add_data(self, array, fmin=None, fmid=None, fmax=None,
                 self._data['time_actor'] = time_actor
                 self._time_label_added = True
             if colorbar and not self._colorbar_added and do:
-                self._renderer.scalarbar(source=actor, n_labels=8,
-                                         color=self._fg_color,
-                                         bgcolor=self._brain_color[:3])
+                kwargs = dict(source=actor, n_labels=8, color=self._fg_color,
+                              bgcolor=self._brain_color[:3])
+                kwargs.update(colorbar_kwargs or {})
+                self._renderer.scalarbar(**kwargs)
                 self._colorbar_added = True
             self._renderer.set_camera(**views_dicts[hemi][v])
         self._update()
@@ -1219,10 +1242,9 @@ def update_lut(self, fmin=None, fmid=None, fmax=None):
         # update our values
         rng = self._cmap_range
         ctable = self._data['ctable']
-        if self._colorbar_added:
-            scalar_bar = self._renderer.plotter.scalar_bar
-        else:
-            scalar_bar = None
+        # in testing, no plotter; if colorbar=False, no scalar_bar
+        scalar_bar = getattr(
+            getattr(self._renderer, 'plotter', None), 'scalar_bar', None)
         for hemi in ['lh', 'rh', 'vol']:
             hemi_data = self._data.get(hemi)
             if hemi_data is not None:
@@ -1271,7 +1293,7 @@ def set_data_smoothing(self, n_steps):
                 maps = sparse.eye(len(self.geo[hemi].coords), format='csr')
                 with use_log_level(False):
                     smooth_mat = _hemi_morph(
-                        self.geo[hemi].faces,
+                        self.geo[hemi].orig_faces,
                         np.arange(len(self.geo[hemi].coords)),
                         vertices, morph_n_steps, maps, warn=False)
                 self._data[hemi]['smooth_mat'] = smooth_mat
@@ -1645,16 +1667,18 @@ def _to_borders(self, label, hemi, borders, restrict_idx=None):
             raise ValueError('borders must be a bool or positive integer')
         if borders:
             n_vertices = label.size
-            edges = mesh_edges(self.geo[hemi].faces)
+            edges = mesh_edges(self.geo[hemi].orig_faces)
             edges = edges.tocoo()
             border_edges = label[edges.row] != label[edges.col]
             show = np.zeros(n_vertices, dtype=np.int64)
             keep_idx = np.unique(edges.row[border_edges])
             if isinstance(borders, int):
                 for _ in range(borders):
-                    keep_idx = np.in1d(self.geo[hemi].faces.ravel(), keep_idx)
-                    keep_idx.shape = self.geo[hemi].faces.shape
-                    keep_idx = self.geo[hemi].faces[np.any(keep_idx, axis=1)]
+                    keep_idx = np.in1d(
+                        self.geo[hemi].orig_faces.ravel(), keep_idx)
+                    keep_idx.shape = self.geo[hemi].orig_faces.shape
+                    keep_idx = self.geo[hemi].orig_faces[
+                        np.any(keep_idx, axis=1)]
                     keep_idx = np.unique(keep_idx)
                 if restrict_idx is not None:
                     keep_idx = keep_idx[np.in1d(keep_idx, restrict_idx)]
diff --git a/mne/viz/_brain/_timeviewer.py b/mne/viz/_brain/_timeviewer.py
index eb0e690e4b1..32b5ab049a6 100644
--- a/mne/viz/_brain/_timeviewer.py
+++ b/mne/viz/_brain/_timeviewer.py
@@ -429,13 +429,16 @@ def ensure_minimum_sizes(self):
                 yield
             finally:
                 self.splitter.setSizes([sz[1], mpl_h])
+                _process_events(self.plotter)
+                _process_events(self.plotter)
                 self.mpl_canvas.canvas.setMinimumSize(0, 0)
             _process_events(self.plotter)
+            _process_events(self.plotter)
+            # sizes could change, update views
             for hemi in ('lh', 'rh'):
-                if hemi == 'rh' and self.brain._hemi == 'split':
-                    continue
                 for ri, ci, v in self.brain._iter_views(hemi):
                     self.brain.show_view(view=v, row=ri, col=ci)
+            _process_events(self.plotter)
 
     def toggle_interface(self, value=None):
         if value is None:
@@ -660,6 +663,9 @@ def configure_sliders(self):
         for hemi in hemis_ref:
             for ri, ci, view in self.brain._iter_views(hemi):
                 self.plotter.subplot(ri, ci)
+                if view == 'flat':
+                    self.orientation_call = None
+                    continue
                 self.orientation_call = ShowView(
                     plotter=self.plotter,
                     brain=self.brain,
@@ -1297,9 +1303,10 @@ def clean(self):
         self.reps = None
         self._time_slider = None
         self._playback_speed_slider = None
-        self.orientation_call.plotter = None
-        self.orientation_call.brain = None
-        self.orientation_call = None
+        if self.orientation_call is not None:
+            self.orientation_call.plotter = None
+            self.orientation_call.brain = None
+            self.orientation_call = None
         self.smoothing_call.plotter = None
         self.smoothing_call = None
         if self.time_call is not None:
diff --git a/mne/viz/_brain/colormap.py b/mne/viz/_brain/colormap.py
index 23f1fbdb5ab..d5de54c7e7c 100644
--- a/mne/viz/_brain/colormap.py
+++ b/mne/viz/_brain/colormap.py
@@ -11,6 +11,7 @@
 def create_lut(cmap, n_colors=256, center=None):
     """Return a colormap suitable for setting as a LUT."""
     from matplotlib import cm
+    assert not (isinstance(cmap, str) and cmap == 'auto')
     cmap = cm.get_cmap(cmap)
     lut = np.round(cmap(np.linspace(0, 1, n_colors)) * 255.0).astype(np.int64)
     return lut
diff --git a/mne/viz/_brain/surface.py b/mne/viz/_brain/surface.py
index de5b9cfde03..9bf533f2ac2 100644
--- a/mne/viz/_brain/surface.py
+++ b/mne/viz/_brain/surface.py
@@ -9,8 +9,9 @@
 from os import path as path
 
 import numpy as np
-from ...utils import _check_option, get_subjects_dir
-from ...surface import complete_surface_info, read_surface, read_curvature
+from ...utils import _check_option, get_subjects_dir, _check_fname
+from ...surface import (complete_surface_info, read_surface, read_curvature,
+                        _read_patch)
 
 
 class Surface(object):
@@ -108,9 +109,17 @@ def load_geometry(self):
         -------
         None
         """
-        surf_path = path.join(self.data_path, 'surf',
-                              '%s.%s' % (self.hemi, self.surf))
-        coords, faces = read_surface(surf_path)
+        if self.surf == 'flat':  # special case
+            fname = path.join(self.data_path, 'surf',
+                              '%s.%s' % (self.hemi, 'cortex.patch.flat'))
+            _check_fname(fname, overwrite='read', must_exist=True,
+                         name='flatmap surface file')
+            coords, faces, orig_faces = _read_patch(fname)
+        else:
+            coords, faces = read_surface(
+                path.join(self.data_path, 'surf',
+                          '%s.%s' % (self.hemi, self.surf)))
+            orig_faces = faces
         if self.units == 'm':
             coords /= 1000.
         if self.offset is not None:
@@ -121,15 +130,10 @@ def load_geometry(self):
         surf = dict(rr=coords, tris=faces)
         complete_surface_info(surf, copy=False, verbose=False)
         nn = surf['nn']
-
-        if self.coords is None:
-            self.coords = coords
-            self.faces = faces
-            self.nn = nn
-        else:
-            self.coords[:] = coords
-            self.faces[:] = faces
-            self.nn[:] = nn
+        self.coords = coords
+        self.faces = faces
+        self.orig_faces = orig_faces
+        self.nn = nn
 
     def __len__(self):
         """Return number of vertices."""
diff --git a/mne/viz/_brain/tests/test_brain.py b/mne/viz/_brain/tests/test_brain.py
index 2ecbc1dfd1f..4e93000c765 100644
--- a/mne/viz/_brain/tests/test_brain.py
+++ b/mne/viz/_brain/tests/test_brain.py
@@ -138,14 +138,17 @@ def test_brain_init(renderer, tmpdir, pixel_ratio):
         with pytest.raises(ValueError, match='remove_existing'):
             brain.add_data(hemi_data, hemi=h, remove_existing=-1)
         with pytest.raises(ValueError, match='time_label_size'):
-            brain.add_data(hemi_data, hemi=h, time_label_size=-1)
+            brain.add_data(hemi_data, hemi=h, time_label_size=-1,
+                           vertices=hemi_vertices)
         with pytest.raises(ValueError, match='is positive'):
-            brain.add_data(hemi_data, hemi=h, smoothing_steps=-1)
+            brain.add_data(hemi_data, hemi=h, smoothing_steps=-1,
+                           vertices=hemi_vertices)
         with pytest.raises(TypeError, match='int or NoneType'):
             brain.add_data(hemi_data, hemi=h, smoothing_steps='foo')
-        with pytest.raises(ValueError):
-            brain.add_data(array=np.array([0, 1, 2]), hemi=h)
-        with pytest.raises(ValueError):
+        with pytest.raises(ValueError, match='dimension mismatch'):
+            brain.add_data(array=np.array([0, 1, 2]), hemi=h,
+                           vertices=hemi_vertices)
+        with pytest.raises(ValueError, match='vertices parameter must not be'):
             brain.add_data(hemi_data, fmin=fmin, hemi=hemi,
                            fmax=fmax, vertices=None)
         with pytest.raises(ValueError, match='has shape'):
@@ -154,7 +157,7 @@ def test_brain_init(renderer, tmpdir, pixel_ratio):
 
         brain.add_data(hemi_data, fmin=fmin, hemi=h, fmax=fmax,
                        colormap='hot', vertices=hemi_vertices,
-                       smoothing_steps='nearest', colorbar=False, time=None)
+                       smoothing_steps='nearest', colorbar=(0, 0), time=None)
         assert brain.data['lh']['array'] is hemi_data
         assert brain.views == ['lateral']
         assert brain.hemis == ('lh',)
@@ -220,8 +223,7 @@ def test_brain_init(renderer, tmpdir, pixel_ratio):
     if renderer._get_3d_backend() == 'mayavi':
         pixel_ratio = 1.  # no HiDPI when using the testing backend
     want_size = np.array([size[0] * pixel_ratio, size[1] * pixel_ratio, 3])
-    assert_allclose(img.shape, want_size,
-                    atol=70 * pixel_ratio)  # XXX undo once size is fixed
+    assert_allclose(img.shape, want_size)
     brain.close()
 
 
diff --git a/mne/viz/_brain/view.py b/mne/viz/_brain/view.py
index acba52030a3..5bbd0f73580 100644
--- a/mne/viz/_brain/view.py
+++ b/mne/viz/_brain/view.py
@@ -6,39 +6,45 @@
 #
 # License: Simplified BSD
 
+ORIGIN = (0., 0., 0.)
+
 _lh_views_dict = {
-    'lateral': dict(azimuth=180., elevation=90.),
-    'medial': dict(azimuth=0., elevation=90.0),
-    'rostral': dict(azimuth=90., elevation=90.),
-    'caudal': dict(azimuth=270., elevation=90.),
-    'dorsal': dict(azimuth=180., elevation=0.),
-    'ventral': dict(azimuth=180., elevation=180.),
-    'frontal': dict(azimuth=120., elevation=80.),
-    'parietal': dict(azimuth=-120., elevation=60.),
-    'sagittal': dict(azimuth=180., elevation=-90.),
-    'coronal': dict(azimuth=90., elevation=-90.),
-    'axial': dict(azimuth=180., elevation=0., roll=180),
+    'lateral': dict(azimuth=180., elevation=90., focalpoint=ORIGIN),
+    'medial': dict(azimuth=0., elevation=90.0, focalpoint=ORIGIN),
+    'rostral': dict(azimuth=90., elevation=90., focalpoint=ORIGIN),
+    'caudal': dict(azimuth=270., elevation=90., focalpoint=ORIGIN),
+    'dorsal': dict(azimuth=180., elevation=0., focalpoint=ORIGIN),
+    'ventral': dict(azimuth=180., elevation=180., focalpoint=ORIGIN),
+    'frontal': dict(azimuth=120., elevation=80., focalpoint=ORIGIN),
+    'parietal': dict(azimuth=-120., elevation=60., focalpoint=ORIGIN),
+    'sagittal': dict(azimuth=180., elevation=-90., focalpoint=ORIGIN),
+    'coronal': dict(azimuth=90., elevation=-90., focalpoint=ORIGIN),
+    'axial': dict(azimuth=180., elevation=0., focalpoint=ORIGIN,
+                  roll=180),
 }
 _rh_views_dict = {
-    'lateral': dict(azimuth=180., elevation=-90.),
-    'medial': dict(azimuth=0., elevation=-90.0),
-    'rostral': dict(azimuth=-90., elevation=-90.),
-    'caudal': dict(azimuth=90., elevation=-90.),
-    'dorsal': dict(azimuth=180., elevation=0.),
-    'ventral': dict(azimuth=180., elevation=180.),
-    'frontal': dict(azimuth=60., elevation=80.),
-    'parietal': dict(azimuth=-60., elevation=60.),
-    'sagittal': dict(azimuth=180., elevation=-90.),
-    'coronal': dict(azimuth=90., elevation=-90.),
-    'axial': dict(azimuth=180., elevation=0., roll=180),
+    'lateral': dict(azimuth=180., elevation=-90., focalpoint=ORIGIN),
+    'medial': dict(azimuth=0., elevation=-90.0, focalpoint=ORIGIN),
+    'rostral': dict(azimuth=-90., elevation=-90., focalpoint=ORIGIN),
+    'caudal': dict(azimuth=90., elevation=-90., focalpoint=ORIGIN),
+    'dorsal': dict(azimuth=180., elevation=0., focalpoint=ORIGIN),
+    'ventral': dict(azimuth=180., elevation=180., focalpoint=ORIGIN),
+    'frontal': dict(azimuth=60., elevation=80., focalpoint=ORIGIN),
+    'parietal': dict(azimuth=-60., elevation=60., focalpoint=ORIGIN),
+    'sagittal': dict(azimuth=180., elevation=-90., focalpoint=ORIGIN),
+    'coronal': dict(azimuth=90., elevation=-90., focalpoint=ORIGIN),
+    'axial': dict(azimuth=180., elevation=0., focalpoint=ORIGIN,
+                  roll=180),
 }
 # add short-size version entries into the dict
 lh_views_dict = _lh_views_dict.copy()
 for k, v in _lh_views_dict.items():
     lh_views_dict[k[:3]] = v
+    lh_views_dict['flat'] = dict(azimuth=250, elevation=0, focalpoint=ORIGIN)
 
 rh_views_dict = _rh_views_dict.copy()
 for k, v in _rh_views_dict.items():
     rh_views_dict[k[:3]] = v
+    rh_views_dict['flat'] = dict(azimuth=-70, elevation=0, focalpoint=ORIGIN)
 views_dicts = dict(lh=lh_views_dict, vol=lh_views_dict, both=lh_views_dict,
                    rh=rh_views_dict)
diff --git a/mne/viz/backends/_pyvista.py b/mne/viz/backends/_pyvista.py
index c103307dc0f..48e27255bb8 100644
--- a/mne/viz/backends/_pyvista.py
+++ b/mne/viz/backends/_pyvista.py
@@ -198,11 +198,24 @@ def ensure_minimum_sizes(self):
         # plotter.ren_win:    vtkXOpenGLRenderWindow
         self.plotter.interactor.setMinimumSize(*sz)
         try:
-            yield
+            yield  # show
         finally:
-            for _ in range(2):
-                _process_events(self.plotter)
+            # 1. Process events
+            _process_events(self.plotter)
+            _process_events(self.plotter)
+            # 2. Get the window size that accommodates the size
+            sz = self.plotter.app_window.size()
+            # 3. Call app_window.setBaseSize and resize (in pyvistaqt)
+            self.plotter.window_size = (sz.width(), sz.height())
+            # 4. Undo the min size setting and process events
             self.plotter.interactor.setMinimumSize(0, 0)
+            _process_events(self.plotter)
+            _process_events(self.plotter)
+            # 5. Resize the window (again!) to the correct size
+            #    (not sure why, but this is required on macOS at least)
+            self.plotter.window_size = (sz.width(), sz.height())
+            _process_events(self.plotter)
+            _process_events(self.plotter)
 
     def subplot(self, x, y):
         x = np.max([0, np.min([x, self.shape[0] - 1])])
@@ -510,25 +523,22 @@ def text3d(self, x, y, z, text, scale, color='white'):
                                           shape_opacity=0)
 
     def scalarbar(self, source, color="white", title=None, n_labels=4,
-                  bgcolor=None):
+                  bgcolor=None, **extra_kwargs):
         with warnings.catch_warnings():
             warnings.filterwarnings("ignore", category=FutureWarning)
-            self.plotter.add_scalar_bar(color=color, title=title,
-                                        n_labels=n_labels,
-                                        use_opacity=False, n_colors=256,
-                                        position_x=0.15,
-                                        position_y=0.05, width=0.7,
-                                        shadow=False, bold=True,
-                                        label_font_size=22,
-                                        font_family=self.font_family,
-                                        background_color=bgcolor)
+            kwargs = dict(color=color, title=title, n_labels=n_labels,
+                          use_opacity=False, n_colors=256, position_x=0.15,
+                          position_y=0.05, width=0.7, shadow=False, bold=True,
+                          label_font_size=22, font_family=self.font_family,
+                          background_color=bgcolor)
+            kwargs.update(extra_kwargs)
+            self.plotter.add_scalar_bar(**kwargs)
 
     def show(self):
         self.figure.display = self.plotter.show()
         if hasattr(self.plotter, "app_window"):
             with self.ensure_minimum_sizes():
                 self.plotter.app_window.show()
-                _process_events(self.plotter, show=True)
         return self.scene()
 
     def close(self):
@@ -663,7 +673,8 @@ def _get_camera_direction(focalpoint, position):
 
 def _set_3d_view(figure, azimuth, elevation, focalpoint, distance, roll=None):
     position = np.array(figure.plotter.camera_position[0])
-    focalpoint = np.array(figure.plotter.camera_position[1])
+    if focalpoint is None:
+        focalpoint = np.array(figure.plotter.camera_position[1])
     r, theta, phi, fp = _get_camera_direction(focalpoint, position)
 
     if azimuth is not None:
@@ -739,13 +750,11 @@ def _take_3d_screenshot(figure, mode='rgb', filename=None):
             filename=filename)
 
 
-def _process_events(plotter, show=False):
+def _process_events(plotter):
     if hasattr(plotter, 'app'):
         with warnings.catch_warnings(record=True):
             warnings.filterwarnings('ignore', 'constrained_layout')
             plotter.app.processEvents()
-        if show:
-            plotter.app_window.show()
 
 
 def _set_colormap_range(actor, ctable, scalar_bar, rng=None):
diff --git a/mne/viz/tests/test_3d.py b/mne/viz/tests/test_3d.py
index 06ebaa5290a..029b9c18e2c 100644
--- a/mne/viz/tests/test_3d.py
+++ b/mne/viz/tests/test_3d.py
@@ -705,9 +705,10 @@ def test_plot_source_estimates(renderer_interactive, all_src_types_inv_evoked,
     with pytest.warns(None):  # PCA mag
         stc = apply_inverse(evoked, inv, pick_ori=pick_ori)
     stc.data[1] *= -1  # make it signed
-    meth = 'plot_3d' if isinstance(stc, _BaseVolSourceEstimate) else 'plot'
-    meth = getattr(stc, meth)
-    kwargs = dict(subject='sample', subjects_dir=subjects_dir,
+    meth_key = 'plot_3d' if isinstance(stc, _BaseVolSourceEstimate) else 'plot'
+    stc.subject = 'sample'
+    meth = getattr(stc, meth_key)
+    kwargs = dict(subjects_dir=subjects_dir,
                   time_viewer=False, show_traces=False,  # for speed
                   smoothing_steps=1, verbose='error', src=inv['src'],
                   volume_options=dict(resolution=None),  # for speed
@@ -740,6 +741,31 @@ def test_plot_source_estimates(renderer_interactive, all_src_types_inv_evoked,
         with pytest.raises(ValueError, match='view_layout must be'):
             meth(view_layout='horizontal', **kwargs)
 
+    # flatmaps (mostly a lot of error checking)
+    these_kwargs = kwargs.copy()
+    these_kwargs.update(surface='flat', views='auto')
+    if kind == 'surface' and pick_ori != 'vector' and is_pyvista:
+        with pytest.raises(FileNotFoundError, match='flatmap'):
+            meth(**these_kwargs)  # sample does not have them
+    fs_stc = stc.copy()
+    fs_stc.subject = 'fsaverage'  # this is wrong, but don't have to care
+    flat_meth = getattr(fs_stc, meth_key)
+    these_kwargs.pop('src')
+    if pick_ori == 'vector':
+        pass  # can't even pass "surface" variable
+    elif kind != 'surface':
+        with pytest.raises(TypeError, match='SourceEstimate when a flatmap'):
+            flat_meth(**these_kwargs)
+    elif not is_pyvista:
+        with pytest.raises(RuntimeError, match='PyVista 3D backend.*flatmap'):
+            flat_meth(**these_kwargs)
+    else:
+        brain = flat_meth(**these_kwargs)
+        brain.close()
+        these_kwargs.update(surface='inflated', views='flat')
+        with pytest.raises(ValueError, match='surface="flat".*views="flat"'):
+            flat_meth(**these_kwargs)
+
     # just test one for speed
     if kind != 'mixed':
         return
diff --git a/tutorials/source-modeling/plot_visualize_stc.py b/tutorials/source-modeling/plot_visualize_stc.py
index 2d530b9f80c..85e8cca8f21 100644
--- a/tutorials/source-modeling/plot_visualize_stc.py
+++ b/tutorials/source-modeling/plot_visualize_stc.py
@@ -50,7 +50,21 @@
 # and ``pysurfer`` installed on your machine.
 initial_time = 0.1
 brain = stc.plot(subjects_dir=subjects_dir, initial_time=initial_time,
-                 clim=dict(kind='value', pos_lims=[3, 6, 9]))
+                 clim=dict(kind='value', lims=[3, 6, 9]))
+
+###############################################################################
+# You can also morph it to fsaverage and visualize it using a flatmap:
+
+# sphinx_gallery_thumbnail_number = 2
+
+stc_fs = mne.compute_source_morph(stc, 'sample', 'fsaverage', subjects_dir,
+                                  smooth=5, verbose='error').apply(stc)
+brain = stc_fs.plot(subjects_dir=subjects_dir, initial_time=initial_time,
+                    clim=dict(kind='value', lims=[3, 6, 9]),
+                    surface='flat', hemi='split', size=(1000, 500),
+                    smoothing_steps=5, time_viewer=False,
+                    add_data_kwargs=dict(
+                        colorbar_kwargs=dict(label_font_size=10)))
 
 ###############################################################################
 #