@@ -38,7 +38,7 @@ def get_registered_canvas_class(format: str) -> type[FigureCanvasBase]: ...
 
 class RendererBase:
     def __init__(self) -> None: ...
-    def open_group(self, s: str, gid: int | None = ...) -> None: ...
+    def open_group(self, s: str, gid: str | None = ...) -> None: ...
     def close_group(self, s: str) -> None: ...
     def draw_path(
         self,
 
@@ -16,7 +16,7 @@ from matplotlib.colors import Colormap, Normalize
 from matplotlib.colorbar import Colorbar
 from matplotlib.cm import ScalarMappable
 from matplotlib.gridspec import GridSpec, SubplotSpec
-from matplotlib.image import _ImageBase
+from matplotlib.image import _ImageBase, FigureImage
 from matplotlib.layout_engine import (
     ConstrainedLayoutEngine,
     LayoutEngine,
@@ -70,7 +70,10 @@ class SubplotParams:
     ) -> None: ...
 
 class FigureBase(Artist):
-    figure: FigureBase | None
+    # Small slight-of-hand as FigureBase is not instantiated directly
+    # hinting as Figure means e.g. plt.figure can be type hinted more easily
+    # FigureBase is never instantiated directly in internal code at the very least
+    figure: Figure
     artists: list[Artist]
     lines: list[Line2D]
     patches: list[Patch]
@@ -152,15 +155,15 @@ class FigureBase(Artist):
         *,
         sharex: bool | Literal["none", "all", "row", "col"] = ...,
         sharey: bool | Literal["none", "all", "row", "col"] = ...,
-        squeeze: Literal[True] = ...,
+        squeeze: bool = ...,
         width_ratios: ArrayLike | None = ...,
         height_ratios: ArrayLike | None = ...,
         subplot_kw: dict[str, Any] | None = ...,
         gridspec_kw: dict[str, Any] | None = ...
     ) -> np.ndarray | SubplotBase | Axes: ...
     def delaxes(self, ax: Axes) -> None: ...
     def clear(self, keep_observers: bool = ...) -> None: ...
-    def clf(self, keep_observers: bool = ...): ...
+    def clf(self, keep_observers: bool = ...) -> None: ...
 
     @overload
     def legend(self) -> Legend: ...
@@ -201,7 +204,7 @@ class FigureBase(Artist):
     def align_xlabels(self, axs: Iterable[Axes] | None = ...) -> None: ...
     def align_ylabels(self, axs: Iterable[Axes] | None = ...) -> None: ...
     def align_labels(self, axs: Iterable[Axes] | None = ...) -> None: ...
-    def add_gridspec(self, nrows: int = ..., ncols: int = ..., **kwargs): ...
+    def add_gridspec(self, nrows: int = ..., ncols: int = ..., **kwargs) -> GridSpec: ...
     @overload
     def subfigures(
         self,
@@ -232,7 +235,7 @@ class FigureBase(Artist):
     def _gci(self) -> ScalarMappable | None: ...
     def _process_projection_requirements(
         self, *args, axes_class=None, polar=False, projection=None, **kwargs
-    ): ...
+    ) -> tuple[type[Axes], dict[str, Any]]: ...
     def get_default_bbox_extra_artists(self) -> list[Artist]: ...
     def get_tightbbox(
         self,
@@ -256,7 +259,7 @@ class FigureBase(Artist):
     ) -> dict[Any, Axes]: ...
 
 class SubFigure(FigureBase):
-    figure: FigureBase
+    figure: Figure
     subplotpars: SubplotParams
     dpi_scale_trans: Affine2D
     canvas: FigureCanvasBase
@@ -355,7 +358,7 @@ class Figure(FigureBase):
         origin: Literal["upper", "lower"] | None = ...,
         resize: bool = ...,
         **kwargs
-    ): ...
+    ) -> FigureImage: ...
     def set_size_inches(
         self, w: float | tuple[float, float], h: float | None = ..., forward: bool = ...
     ) -> None: ...
@@ -369,7 +372,7 @@ class Figure(FigureBase):
     def clear(self, keep_observers: bool = ...) -> None: ...
     def draw_without_rendering(self) -> None: ...
     def draw_artist(self, a: Artist) -> None: ...
-    def add_axobserver(self, func: Callable[[Figure], Any]): ...
+    def add_axobserver(self, func: Callable[[Figure], Any]) -> None: ...
     def savefig(
         self,
         fname: str | os.PathLike | io.FileIO,
@@ -386,7 +389,7 @@ class Figure(FigureBase):
         mouse_pop: MouseButton = ...,
         mouse_stop: MouseButton = ...,
     ) -> list[tuple[int, int]]: ...
-    def waitforbuttonpress(self, timeout: float = ...): ...
+    def waitforbuttonpress(self, timeout: float = ...) -> None | bool: ...
     def tight_layout(
         self,
         *,
 
@@ -117,7 +117,7 @@
     from matplotlib.figure import SubFigure
     from matplotlib.legend import Legend
     from matplotlib.mlab import GaussianKDE
-    from matplotlib.image import AxesImage
+    from matplotlib.image import AxesImage, FigureImage
     from matplotlib.patches import FancyArrow, StepPatch
     from matplotlib.quiver import Barbs, Quiver, QuiverKey
     from matplotlib.scale import ScaleBase
@@ -755,7 +755,7 @@ def figure(
     FigureClass: Type[Figure] = Figure,
     clear: bool = False,
     **kwargs
-):
+) -> Figure:
     """
     Create a new figure, or activate an existing figure.
 
@@ -2346,7 +2346,7 @@ def matshow(A: ArrayLike, fignum: None | int = None, **kwargs) -> AxesImage:
         # Extract actual aspect ratio of array and make appropriately sized
         # figure.
         fig = figure(fignum, figsize=figaspect(A))
-        ax = fig.add_axes([0.15, 0.09, 0.775, 0.775])
+        ax = fig.add_axes((0.15, 0.09, 0.775, 0.775))
     im = ax.matshow(A, **kwargs)
     sci(im)
     return im
@@ -2402,7 +2402,7 @@ def figimage(
     origin: Literal["upper", "lower"] | None = None,
     resize: bool = False,
     **kwargs,
-):
+) -> FigureImage:
     return gcf().figimage(
         X,
         xo=xo,
@@ -2493,7 +2493,7 @@ def tight_layout(
 
 # Autogenerated by boilerplate.py.  Do not edit as changes will be lost.
 @_copy_docstring_and_deprecators(Figure.waitforbuttonpress)
-def waitforbuttonpress(timeout: float = -1):
+def waitforbuttonpress(timeout: float = -1) -> None | bool:
     return gcf().waitforbuttonpress(timeout=timeout)