Added png for 2D surfaces

src/scientific_plots/__init__.py

@@ -5,4 +5,4 @@ useful across several different projects and repositories. It also contains
 stub-files with several data-type annotations for scipy and matplot-lib
 functions."""
 
-__version__ = "1.8.7"
+__version__ = "1.8.8"

src/scientific_plots/plot_settings.py

@@ -553,8 +553,8 @@ def apply_styles(plot_function: Optional[Callable[Params, None]] = None, *,
 
     Arguments
     --------
-    three_d: Create a use this option for 3D-plots
-    fallback: switch directly to the fallback-style (for debug)
+    three_d: Use this option for 3D-plots.
+    fallback: Switch directly to the fallback-style (for debug).
     """
     # pylint: disable=too-many-statements
 
@@ -614,11 +614,14 @@ def apply_styles(plot_function: Optional[Callable[Params, None]] = None, *,
                     plt.set_cmap("Greys")
                     new_kwargs = copy(kwargs)
                     new_kwargs["colorscheme"] = "Greys"
+                    plt.savefig = new_save_simple("grayscale", png=True,
+                                                  small=False,
+                                                  slim=True)
                 else:
                     new_kwargs = kwargs
                     plt.savefig = new_save_simple("grayscale", png=False,
-                                              small=not three_d,
-                                              slim=not three_d)
+                                                  small=True,
+                                                  slim=True)
                 _plot_function(*args, **new_kwargs)
                 plt.close("all")