diff --git a/simopt/experiment_base.py b/simopt/experiment_base.py
index b13ceab88..ff6827d24 100644
--- a/simopt/experiment_base.py
+++ b/simopt/experiment_base.py
@@ -1355,13 +1355,27 @@ class PlotType(Enum):
     SOLVE_TIME_CDF = "solve_time_cdf"
     CDF_SOLVABILITY = "cdf_solvability"
     QUANTILE_SOLVABILITY = "quantile_solvability"
-    DIFF_CDF_SOLVABILITY = "diff_cdf_solvability"
-    DIFF_QUANTILE_SOLVABILITY = "diff_quantile_solvability"
+    DIFF_CDF_SOLVABILITY = "difference_of_cdf_solvability"
+    DIFF_QUANTILE_SOLVABILITY = "difference_of_quantile_solvability"
     AREA = "area"
     BOX = "box"
     VIOLIN = "violin"
     TERMINAL_SCATTER = "terminal_scatter"
 
+    @staticmethod
+    def from_str(label: str) -> PlotType:
+        """Converts a string label to a PlotType enum."""
+        # Reverse mapping from string to PlotType enum.
+        name = label.lower().replace(" ", "_")
+        inv_plot_type = {pt.value: pt for pt in PlotType}
+        if name in inv_plot_type:
+            return inv_plot_type[name]
+        error_msg = (
+            f"Unknown plot type: {label} ({name}). "
+            f"Must be one of {[pt.value for pt in PlotType]}."
+        )
+        raise ValueError(error_msg)
+
 
 def bootstrap_procedure(
     experiments: list[list[ProblemSolver]],
@@ -3621,35 +3635,29 @@ def save_plot(
         plot_name = plot_name + "_unnorm"
 
     # Reformat plot_name to be suitable as a string literal.
-    plot_name = plot_name.replace("\\", "")
-    plot_name = plot_name.replace("$", "")
-    plot_name = plot_name.replace(" ", "_")
+    plot_name = plot_name.replace("\\", "").replace("$", "").replace(" ", "_")
 
     # If the plot title is not provided, use the default title.
     if plot_title is None:
         plot_title = f"{solver_name}_{problem_name}_{plot_name}"
-    path_name = plot_dir / plot_title
 
-    # Check to make sure file does not override previous images
-    counter = 0
-    while True:
-        # add extension to path name
-        extended_path_name = path_name.with_suffix(ext)
-
-        # If file doesn't exist, break out of loop
-        if not extended_path_name.exists():
-            break
+    # Read in the contents of the plot directory
+    existing_plots = [path.name for path in list(plot_dir.glob("*"))]
+    print(f"Existing plots: {existing_plots}")
 
-        # If file exists, increment counter and try again
+    counter = 0
+    while (plot_title + ext) in existing_plots:
+        # If the plot title already exists, append a counter to the filename
         counter += 1
-        path_name = plot_dir / f"{plot_title} ({counter})"
+        plot_title = f"{plot_title} ({counter})"
+    extended_path_name = plot_dir / (plot_title + ext)
 
     plt.savefig(extended_path_name, bbox_inches="tight")
 
     # save plot as pickle
     if save_as_pickle:
         fig = plt.gcf()
-        pickle_path = path_name.with_suffix(".pkl")
+        pickle_path = extended_path_name.with_suffix(".pkl")
         with pickle_path.open("wb") as pickle_file:
             pickle.dump(fig, pickle_file)
     # Return path_name for use in GUI.
diff --git a/simopt/gui/new_experiment_window.py b/simopt/gui/new_experiment_window.py
index 068b659eb..f5aa1b606 100644
--- a/simopt/gui/new_experiment_window.py
+++ b/simopt/gui/new_experiment_window.py
@@ -20,6 +20,7 @@
 from simopt.base import Problem, Solver
 from simopt.data_farming_base import DATA_FARMING_DIR
 from simopt.experiment_base import (
+    PlotType,
     ProblemSolver,
     ProblemsSolvers,
     create_design,
@@ -4027,7 +4028,7 @@ def show_plot_options(self, plot_type_tk: tk.StringVar) -> None:
             subplot_type_options = [
                 "CDF Solvability",
                 "Quantile Solvability",
-                "Difference of CDF Solvablility",
+                "Difference of CDF Solvability",
                 "Difference of Quantile Solvability",
             ]
             self.subplot_type_var = tk.StringVar()
@@ -4317,7 +4318,7 @@ def enable_ref_solver(self, plot_type_tk: tk.StringVar) -> None:
         if plot_type in ["CDF Solvability", "Quantile Solvability"]:
             self.ref_solver_menu.configure(state="disabled")
         elif plot_type in [
-            "Difference of CDF Solvablility",
+            "Difference of CDF Solvability",
             "Difference of Quantile Solvability",
         ]:
             self.ref_solver_menu.configure(state="normal")
@@ -4456,6 +4457,10 @@ def __plot_progress_curve(self) -> None:
             parameters["Quantile Probability"] = beta
         parameters["Number Bootstrap Samples"] = n_boot
         parameters["Confidence Level"] = con_level
+        # Lookup plot type enum for passing to plotting function
+        subplot_type_enum: PlotType = PlotType.from_str(
+            subplot_type.lower()
+        )
         # create new plot for each problem
         for i in range(n_problems):
             prob_list = []
@@ -4463,7 +4468,7 @@ def __plot_progress_curve(self) -> None:
                 prob_list.append(solver_group[i])
             returned_path = plot_progress_curves(
                 experiments=prob_list,
-                plot_type=subplot_type,  # type: ignore
+                plot_type=subplot_type_enum,
                 beta=beta,
                 normalize=norm,
                 all_in_one=all_in,
@@ -4642,6 +4647,10 @@ def __plot_terminal_progress(self) -> None:
         parameters["Plot Type"] = subplot_type
         assert subplot_type in ["box", "violin"]
         parameters["Normalize Optimality Gaps"] = normalize_str
+        # Lookup plot type enum for passing to plotting function
+        subplot_type_enum: PlotType = PlotType.from_str(
+            subplot_type.lower()
+        )
         # create a new plot for each problem
         for i in range(n_problems):
             prob_list = []
@@ -4649,7 +4658,7 @@ def __plot_terminal_progress(self) -> None:
                 prob_list.append(solver_group[i])
             returned_path = plot_terminal_progress(
                 experiments=prob_list,
-                plot_type=subplot_type,  # type: ignore
+                plot_type=subplot_type_enum,
                 all_in_one=all_in,
                 normalize=norm,
                 save_as_pickle=True,
@@ -4736,7 +4745,7 @@ def __plot_solvability_profile(self) -> None:
         subplot_types = {
             "CDF Solvability": "cdf_solvability",
             "Quantile Solvability": "quantile_solvability",
-            "Difference of CDF Solvablility": "diff_cdf_solvability",
+            "Difference of CDF Solvability": "diff_cdf_solvability",
             "Difference of Quantile Solvability": "diff_quantile_solvability",
         }
         subplot_type = self.subplot_type_var.get()
@@ -4768,11 +4777,12 @@ def __plot_solvability_profile(self) -> None:
             "Difference of Quantile Solvability",
         ]:
             parameters["Quantile Probability"] = beta
-
+        # Lookup plot type enum for passing to plotting function
+        subplot_type_enum = PlotType.from_str(subplot_type)
         if subplot_type in ["CDF Solvability", "Quantile Solvability"]:
             returned_path = plot_solvability_profiles(
                 experiments=exp_sublist,
-                plot_type=plot_input,  # type: ignore
+                plot_type=subplot_type_enum,
                 all_in_one=all_in,
                 n_bootstraps=n_boot,
                 conf_level=con_level,
@@ -4792,7 +4802,7 @@ def __plot_solvability_profile(self) -> None:
             parameters["Reference Solver"] = ref_solver
             returned_path = plot_solvability_profiles(
                 experiments=exp_sublist,
-                plot_type=plot_input,  # type: ignore
+                plot_type=subplot_type_enum,
                 all_in_one=all_in,
                 n_bootstraps=n_boot,
                 conf_level=con_level,