Remove the forced disabling of antialiasing in contourf/pcolormesh/pc…

…olor/tripcolor
ayshih · Sep 1, 2026 · Sep 1, 2026 · Oct 9, 2026 · Oct 9, 2026 · Sep 1, 2026
commit b806969181a78872f019ec2cdcb8e3b5eca10a47
diff --git a/lib/matplotlib/axes/_axes.py b/lib/matplotlib/axes/_axes.py
@@ -6690,15 +6690,6 @@ def pcolor(self, *args, shading=None, alpha=None, norm=None, cmap=None,
 
         Other Parameters
         ----------------
-        antialiaseds : bool, default: False
-            The default *antialiaseds* is False if the default
-            *edgecolors*\ ="none" is used.  This eliminates artificial lines
-            at patch boundaries, and works regardless of the value of alpha.
-            If *edgecolors* is not "none", then the default *antialiaseds*
-            is taken from :rc:`patch.antialiased`.
-            Stroking the edges may be preferred if *alpha* is 1, but will
-            cause artifacts otherwise.
-
         data : indexable object, optional
             DATA_PARAMETER_PLACEHOLDER
 
@@ -6758,15 +6749,6 @@ def pcolor(self, *args, shading=None, alpha=None, norm=None, cmap=None,
             kwargs['edgecolors'] = kwargs.pop('edgecolor')
         ec = kwargs.setdefault('edgecolors', 'none')
 
-        # aa setting will default via collections to patch.antialiased
-        # unless the boundary is not stroked, in which case the
-        # default will be False; with unstroked boundaries, aa
-        # makes artifacts that are often disturbing.
-        if 'antialiaseds' in kwargs:
-            kwargs['antialiased'] = kwargs.pop('antialiaseds')
-        if 'antialiased' not in kwargs and cbook._str_lower_equal(ec, "none"):
-            kwargs['antialiased'] = False
-
         kwargs.setdefault('snap', False)
 
         if np.ma.isMaskedArray(X) or np.ma.isMaskedArray(Y):
@@ -6793,7 +6775,7 @@ def pcolor(self, *args, shading=None, alpha=None, norm=None, cmap=None,
     @_preprocess_data()
     @_docstring.interpd
     def pcolormesh(self, *args, alpha=None, norm=None, cmap=None, vmin=None,
-                   vmax=None, colorizer=None, shading=None, antialiased=False,
+                   vmax=None, colorizer=None, shading=None,
                    **kwargs):
         """
         Create a pseudocolor plot with a non-regular rectangular grid.
@@ -7004,7 +6986,7 @@ def pcolormesh(self, *args, alpha=None, norm=None, cmap=None, vmin=None,
         kwargs.setdefault('snap', mpl.rcParams['pcolormesh.snap'])
 
         collection = mcoll.QuadMesh(
-            coords, antialiased=antialiased, shading=shading,
+            coords, shading=shading,
             array=C, colorizer=colorizer, alpha=alpha, **kwargs)
         collection._scale_norm(norm, vmin, vmax)
 
@@ -7203,7 +7185,7 @@ def pcolorfast(self, *args, alpha=None, norm=None, cmap=None, vmin=None,
             collection = mcoll.QuadMesh(
                 coords, array=C,
                 alpha=alpha, cmap=cmap, norm=norm, colorizer=colorizer,
-                antialiased=False, edgecolors="none")
+                edgecolors="none")
             self.add_collection(collection, autolim=False)
             xl, xr, yb, yt = x.min(), x.max(), y.min(), y.max()
             ret = collection

diff --git a/lib/matplotlib/axes/_axes.pyi b/lib/matplotlib/axes/_axes.pyi
@@ -551,7 +551,6 @@ class Axes(_AxesBase):
         vmax: float | tuple[float, ...] | None = ...,
         colorizer: Colorizer | None = ...,
         shading: Literal["flat", "nearest", "gouraud", "auto"] | None = ...,
-        antialiased: bool = ...,
         data: DataParamType = ...,
         **kwargs
     ) -> QuadMesh: ...

diff --git a/lib/matplotlib/contour.py b/lib/matplotlib/contour.py
@@ -673,11 +673,6 @@ def __init__(self, ax, *args,
             Keyword arguments are as described in the docstring of
             `~.Axes.contour`.
         """
-        if antialiased is None and filled:
-            # Eliminate artifacts; we are not stroking the boundaries.
-            antialiased = False
-            # The default for line contours will be taken from the
-            # LineCollection default, which uses :rc:`lines.antialiased`.
         super().__init__(
             antialiaseds=antialiased,
             alpha=alpha,
@@ -1646,18 +1641,16 @@ def _initialize_x_y(self, z):
     :class:`matplotlib.units.ConversionInterface`.
 
 antialiased : bool, optional
-    Enable antialiasing, overriding the defaults.  For
-    filled contours, the default is *False*.  For line contours,
-    it is taken from :rc:`lines.antialiased`.
+    Enable or disable antialiasing, overriding the defaults.
+    For filled contours, the default value is :rc:`patch.antialiased`.
+    For line contours, the default value is :rc:`lines.antialiased`.
 
 nchunk : int >= 0, optional
     If 0, no subdivision of the domain.  Specify a positive integer to
     divide the domain into subdomains of *nchunk* by *nchunk* quads.
     Chunking reduces the maximum length of polygons generated by the
     contouring algorithm which reduces the rendering workload passed
-    on to the backend and also requires slightly less RAM.  It can
-    however introduce rendering artifacts at chunk boundaries depending
-    on the backend, the *antialiased* flag and value of *alpha*.
+    on to the backend and also requires slightly less RAM.
 
 linewidths : float or array-like, default: :rc:`contour.linewidth`
     *Only applies to* `.contour`.

diff --git a/lib/matplotlib/pyplot.py b/lib/matplotlib/pyplot.py
@@ -3597,7 +3597,7 @@ def hexbin(
     vmax: float | None = None,
     alpha: float | None = None,
     linewidths: float | None = None,
-    edgecolors: Literal["face", "none"] | ColorType = "face",
+    edgecolors: Literal["face", "none"] | ColorType = "none",
     reduce_C_function: Callable[[np.ndarray | list[float]], float] = np.mean,
     mincnt: int | None = None,
     marginals: bool = False,
@@ -3917,7 +3917,6 @@ def pcolormesh(
     vmax: float | tuple[float, ...] | None = None,
     colorizer: Colorizer | None = None,
     shading: Literal["flat", "nearest", "gouraud", "auto"] | None = None,
-    antialiased: bool = False,
     data: DataParamType = None,
     **kwargs,
 ) -> QuadMesh:
@@ -3930,7 +3929,6 @@ def pcolormesh(
         vmax=vmax,
         colorizer=colorizer,
         shading=shading,
-        antialiased=antialiased,
         **({"data": data} if data is not None else {}),
         **kwargs,
     )

diff --git a/lib/matplotlib/tri/_tripcolor.py b/lib/matplotlib/tri/_tripcolor.py
@@ -124,11 +124,6 @@ def tripcolor(ax, *args, alpha=1.0, norm=None, cmap=None, vmin=None,
         kwargs['edgecolors'] = kwargs.pop('edgecolor')
     ec = kwargs.setdefault('edgecolors', edgecolors)
 
-    if 'antialiased' in kwargs:
-        kwargs['antialiaseds'] = kwargs.pop('antialiased')
-    if 'antialiaseds' not in kwargs and ec.lower() == "none":
-        kwargs['antialiaseds'] = False
-
     if shading == 'gouraud':
         if facecolors is not None:
             raise ValueError(