diff --git a/src/gui_qt/_py/basewindow.py b/src/gui_qt/_py/basewindow.py
index 3b24795..d916548 100644
--- a/src/gui_qt/_py/basewindow.py
+++ b/src/gui_qt/_py/basewindow.py
@@ -365,6 +365,9 @@ class Ui_BaseWindow(object):
         self.actionBinning.setObjectName("actionBinning")
         self.actionTNMH = QtWidgets.QAction(BaseWindow)
         self.actionTNMH.setObjectName("actionTNMH")
+        self.actionExclude_region = QtWidgets.QAction(BaseWindow)
+        self.actionExclude_region.setCheckable(True)
+        self.actionExclude_region.setObjectName("actionExclude_region")
         self.menuSave.addAction(self.actionSave)
         self.menuSave.addAction(self.actionExportGraphic)
         self.menuSave.addAction(self.action_save_fit_parameter)
@@ -419,6 +422,7 @@ class Ui_BaseWindow(object):
         self.menuLimits.addAction(self.action_no_range)
         self.menuLimits.addAction(self.action_x_range)
         self.menuLimits.addAction(self.action_custom_range)
+        self.menuLimits.addAction(self.actionExclude_region)
         self.menuFit.addAction(self.action_FitWidget)
         self.menuFit.addSeparator()
         self.menuFit.addAction(self.action_create_fit_function)
@@ -631,6 +635,7 @@ class Ui_BaseWindow(object):
         self.actionTNMH_model.setText(_translate("BaseWindow", "Tg , Hodge, TNMH,,,"))
         self.actionBinning.setText(_translate("BaseWindow", "Binning..."))
         self.actionTNMH.setText(_translate("BaseWindow", "TNMH..."))
+        self.actionExclude_region.setText(_translate("BaseWindow", "Exclude region"))
 from ..data.datawidget.datawidget import DataWidget
 from ..data.integral_widget import IntegralWidget
 from ..data.point_select import PointSelectWidget
diff --git a/src/gui_qt/dsc/glass_dialog.py b/src/gui_qt/dsc/glass_dialog.py
index f815b7a..b7afe09 100644
--- a/src/gui_qt/dsc/glass_dialog.py
+++ b/src/gui_qt/dsc/glass_dialog.py
@@ -136,8 +136,8 @@ class TgCalculator(QtWidgets.QWizard, Ui_DSCEvalDialog):
             max_x = max(max_x, data.x.max())
 
             item = QtWidgets.QListWidgetItem(name)
-            item.setCheckState(QtCore.Qt.Checked)
-            item.setData(QtCore.Qt.UserRole, key)
+            item.setCheckState(QtCore.Qt.CheckState.Checked)
+            item.setData(QtCore.Qt.ItemDataRole.UserRole, key)
             item.setForeground(mkBrush(c.rgb()))
             self.listWidget.addItem(item)
 
@@ -191,10 +191,10 @@ class TgCalculator(QtWidgets.QWizard, Ui_DSCEvalDialog):
 
         for idx in range(self.listWidget.count()):
             item = self.listWidget.item(idx)
-            if item.checkState() == QtCore.Qt.Unchecked:
+            if item.checkState() == QtCore.Qt.CheckState.Unchecked:
                 continue
 
-            key = item.data(QtCore.Qt.UserRole)
+            key = item.data(QtCore.Qt.ItemDataRole.UserRole)
             plot = self._plots[key]
             data, _ = self._dsc[key]
 
@@ -214,7 +214,7 @@ class TgCalculator(QtWidgets.QWizard, Ui_DSCEvalDialog):
             item = self.listWidget.item(idx)
 
             tree_item = QtWidgets.QTreeWidgetItem([item.text()])
-            values = self._tg_value.get(item.data(QtCore.Qt.UserRole))
+            values = self._tg_value.get(item.data(QtCore.Qt.ItemDataRole.UserRole))
 
             if values is not None:
                 for name, pos in values.items():
@@ -223,7 +223,7 @@ class TgCalculator(QtWidgets.QWizard, Ui_DSCEvalDialog):
 
                 self.tg_tree.addTopLevelItem(tree_item)
 
-            key = item.data(QtCore.Qt.UserRole)
+            key = item.data(QtCore.Qt.ItemDataRole.UserRole)
             plot = self._plots[key]
             data, _ = self._dsc[key]
 
@@ -251,7 +251,7 @@ class TgCalculator(QtWidgets.QWizard, Ui_DSCEvalDialog):
     @QtCore.pyqtSlot(QtWidgets.QListWidgetItem)
     def change_visibility(self, item: QtWidgets.QListWidgetItem):
         is_checked = bool(item.checkState())
-        plot = self._plots[item.data(QtCore.Qt.UserRole)]
+        plot = self._plots[item.data(QtCore.Qt.ItemDataRole.UserRole)]
         for val in plot:
             val.setVisible(is_checked)
 
@@ -275,10 +275,10 @@ class TgCalculator(QtWidgets.QWizard, Ui_DSCEvalDialog):
         self.tnmh_tree.clear()
         for idx in range(self.listWidget.count()):
             item = self.listWidget.item(idx)
-            if item.checkState() == QtCore.Qt.Unchecked:
+            if item.checkState() == QtCore.Qt.CheckState.Unchecked:
                 continue
 
-            key = item.data(QtCore.Qt.UserRole)
+            key = item.data(QtCore.Qt.ItemDataRole.UserRole)
 
             data = self.get_fictive(key, baselines)
 
@@ -292,7 +292,7 @@ class TgCalculator(QtWidgets.QWizard, Ui_DSCEvalDialog):
             item = self.listWidget.item(idx)
 
             tree_item = QtWidgets.QTreeWidgetItem([item.text()])
-            values = self._fit.get(item.data(QtCore.Qt.UserRole))
+            values = self._fit.get(item.data(QtCore.Qt.ItemDataRole.UserRole))
 
             if values is not None:
                 child_item = QtWidgets.QTreeWidgetItem([values.parameter_string()])
@@ -305,10 +305,10 @@ class TgCalculator(QtWidgets.QWizard, Ui_DSCEvalDialog):
         ret_dic = {}
         for idx in range(self.listWidget.count()):
             item = self.listWidget.item(idx)
-            if item.checkState() == QtCore.Qt.Unchecked:
+            if item.checkState() == QtCore.Qt.CheckState.Unchecked:
                 continue
 
-            key = item.data(QtCore.Qt.UserRole)
+            key = item.data(QtCore.Qt.ItemDataRole.UserRole)
 
             cp = None
             if self.fictive_export_check.isChecked():
@@ -332,10 +332,10 @@ class TgCalculator(QtWidgets.QWizard, Ui_DSCEvalDialog):
             m = []
             for idx in range(self.listWidget.count()):
                 item = self.listWidget.item(idx)
-                if item.checkState() == QtCore.Qt.Unchecked:
+                if item.checkState() == QtCore.Qt.CheckState.Unchecked:
                     continue
 
-                key = item.data(QtCore.Qt.UserRole)
+                key = item.data(QtCore.Qt.ItemDataRole.UserRole)
                 data, _ = self._dsc[key]
                 try:
                     tg_value = self._tg_value[key][tg_type][0]
diff --git a/src/gui_qt/fit/fit_toolbar.py b/src/gui_qt/fit/fit_toolbar.py
index 4cfa091..283c335 100644
--- a/src/gui_qt/fit/fit_toolbar.py
+++ b/src/gui_qt/fit/fit_toolbar.py
@@ -58,7 +58,8 @@ class FitToolbar(QtWidgets.QToolBar):
 
     @QtCore.pyqtSlot(QtWidgets.QAction)
     def change_limit_type(self, action: QtWidgets.QAction):
-        is_custom = (action.text() == 'Custom')
+        is_custom = (action.text() in ['Custom', 'Exclude region'])
+        print(is_custom)
 
         for w in [self.label, self.label2, self.lineedit, self.lineedit2]:
             w.setEnabled(is_custom)
@@ -93,5 +94,6 @@ class FitToolbar(QtWidgets.QToolBar):
         return {
             'None': 'none',
             'Visible x range': 'x',
-            'Custom': self.region.getRegion(),
+            'Custom': ('in', self.region.getRegion()),
+            'Exclude region': ('out', self.region.getRegion()),
         }[action_text]
diff --git a/src/gui_qt/io/dscreader.py b/src/gui_qt/io/dscreader.py
index a9b83a0..1ebda46 100644
--- a/src/gui_qt/io/dscreader.py
+++ b/src/gui_qt/io/dscreader.py
@@ -264,11 +264,16 @@ class QDSCReader(QtWidgets.QDialog, Ui_Dialog):
         except TypeError:
             return
 
+        if self.cp_checkBox.isChecked() and self.references:
+            y_label = 'cp'
+        else:
+            y_label = 'q'
+
         rate, mode = self.current_run
-        new_val = DSC(sample_data[0], sample_data[1], value=rate, name=f'{self.fname.stem} {rate} ({mode})')
+        new_val = DSC(sample_data[0], sample_data[1], value=rate, name=f'{self.fname.stem} {rate}K-min ({mode}, {y_label})')
 
         if filesave:
-            new_val.savetxt(self.fname.with_name(f'{self.fname.stem} {rate}K-min {mode}.dat'.replace(' ', '_')))
+            new_val.savetxt(self.fname.with_name(f'{self.fname.stem}_{rate}K-min_{y_label}{mode}.dat'.replace(' ', '_')))
             close_after = False
         else:
             self.data_read.emit([new_val])
diff --git a/src/gui_qt/main/mainwindow.py b/src/gui_qt/main/mainwindow.py
index 80935b6..d91b3ac 100644
--- a/src/gui_qt/main/mainwindow.py
+++ b/src/gui_qt/main/mainwindow.py
@@ -888,7 +888,7 @@ class NMRMainWindow(QtWidgets.QMainWindow, Ui_BaseWindow):
             self.fit_dialog.load(self.management.active_sets)
             for item in self.fit_dialog.preview_lines:
                 self.current_graph_widget.add_external(item)
-            if self.action_custom_range.isChecked():
+            if self.action_custom_range.isChecked() or self.actionExclude_region.isChecked():
                 self.current_graph_widget.add_external(self.fit_toolbar.region)
 
             block_window = True
@@ -904,7 +904,7 @@ class NMRMainWindow(QtWidgets.QMainWindow, Ui_BaseWindow):
         if self.current_graph_widget is None:
             return
 
-        if action == self.action_custom_range and self.fit_dialog.isVisible():
+        if action in [self.action_custom_range, self.actionExclude_region] and self.fit_dialog.isVisible():
             self.current_graph_widget.add_external(self.fit_toolbar.region)
         else:
             self.current_graph_widget.remove_external(self.fit_toolbar.region)
diff --git a/src/gui_qt/main/management.py b/src/gui_qt/main/management.py
index b8758b2..ab07037 100644
--- a/src/gui_qt/main/management.py
+++ b/src/gui_qt/main/management.py
@@ -511,13 +511,16 @@ class UpperManagement(QtCore.QObject):
 
                     _x = data_i.x
 
+                    # options for fit limits 'none', 'x', ('in', custom region), ('out', excluded region)
                     if fit_limits == 'none':
                         inside = slice(None)
                     elif fit_limits == 'x':
                         x_lim, _ = self.graphs[self.current_graph].ranges
                         inside = np.where((_x >= x_lim[0]) & (_x <= x_lim[1]))
+                    elif fit_limits[0] == 'in':
+                        inside = np.where((_x >= fit_limits[1][0]) & (_x <= fit_limits[1][1]))
                     else:
-                        inside = np.where((_x >= fit_limits[0]) & (_x <= fit_limits[1]))
+                        inside = np.where((_x < fit_limits[1][0]) | (_x > fit_limits[1][1]))
 
                     try:
                         if isinstance(we, str):
diff --git a/src/nmreval/io/dsc.py b/src/nmreval/io/dsc.py
index b531bd4..4aaf606 100644
--- a/src/nmreval/io/dsc.py
+++ b/src/nmreval/io/dsc.py
@@ -11,7 +11,8 @@ try:
     from scipy.integrate import simpson
 except ImportError:
     from scipy.integrate import simps as simpson
-from scipy.interpolate import interp1d
+from scipy.interpolate import CubicSpline
+
 
 ReferenceValue = namedtuple('Reference', ['name', 'transitions'])
 Cyclohexane = ReferenceValue('Cyclohexane', [(-87.06+273.15, 79.58), (6.54+273.15, None)])
@@ -38,7 +39,7 @@ class DSCSample:
     def read_file(self, fname: str | Path) -> None:
         fname = Path(fname)
 
-        # file contains weird deg C character in stupiod ISO encoding
+        # file contains weird deg C character in stupid ISO encoding
         with fname.open('r', encoding='iso-8859-15') as f:
             ii = 1
             for line in f:
@@ -144,9 +145,12 @@ class DSCCalibrator:
         self.reference = []
         self.ref_list = []
 
-    def set_measurement(self,
-                        fname: str | Path | DSCSample, mode: str = 'sample',
-                        reference: ReferenceValue = Cyclohexane):
+    def set_measurement(
+            self: DSCCalibrator,
+            fname: str | Path | DSCSample,
+            mode: str = 'sample',
+            reference: ReferenceValue = Cyclohexane
+    ):
         if mode not in ['sample', 'empty', 'reference']:
             raise ValueError(f'Unknown mode {mode}, not "sample", "empty", "reference"')
         if mode == 'reference' and not isinstance(reference, ReferenceValue):
@@ -266,7 +270,12 @@ class DSCCalibrator:
 
         return sol
 
-    def get_data(self, idx: int, slope: str = 'iso', limits: tuple[float, float] = None):
+    def get_data(
+            self: DSCCalibrator,
+            idx: int,
+            slope: str = 'iso',
+            limits: tuple[float, float] = None
+    ) -> tuple[np.ndarray, np.ndarray, np.ndarray,np.ndarray | None, np.ndarray]:
         if self.sample.steps[idx][0] == 'i':
             raise ValueError('baseline correction is not implemented for isotherms')
 
@@ -292,7 +301,7 @@ class DSCCalibrator:
             empty_y = empty_data[1]
             if self.sample.length(idx) != self.empty.length(idx_empty):
                 with np.errstate(all='ignore'):
-                    empty_y = interp1d(empty_data[2]-empty_data[2, 0], empty_data[1], fill_value='extrapolate')(sample_data[2, 0])
+                    empty_y = CubicSpline(empty_data[2]-empty_data[2, 0], empty_data[1], extrapolate=True)(sample_data[2] - sample_data[2, 0])
 
         sample_data[1] -= empty_y
         drift_value = sample_data.copy()[(2, 1), :]
@@ -346,9 +355,10 @@ class DSCCalibrator:
 
             offset = region[0, 0]
             sample_data[1] -= m * (sample_data[2] - region[1, 0]) + offset
-            line = np.array([[sample_data[2, 0], sample_data[2, -1]],
-                             [m * (sample_data[2, 0] - region[1, 0]) + offset,
-                              m * (sample_data[2, -1] - region[1, 0]) + offset]])
+            line = np.array([
+                [sample_data[2, 0], sample_data[2, -1]],
+                [m * (sample_data[2, 0] - region[1, 0]) + offset, m * (sample_data[2, -1] - region[1, 0]) + offset]
+            ])
 
         else:
             line = np.array([[sample_data[2, 0], sample_data[2, -1]], [0, 0]])
diff --git a/src/resources/_ui/basewindow.ui b/src/resources/_ui/basewindow.ui
index bf3de79..01987b8 100644
--- a/src/resources/_ui/basewindow.ui
+++ b/src/resources/_ui/basewindow.ui
@@ -247,6 +247,7 @@
      <addaction name="action_no_range"/>
      <addaction name="action_x_range"/>
      <addaction name="action_custom_range"/>
+     <addaction name="actionExclude_region"/>
     </widget>
     <addaction name="action_FitWidget"/>
     <addaction name="separator"/>
@@ -1021,6 +1022,14 @@
     <string>TNMH...</string>
    </property>
   </action>
+  <action name="actionExclude_region">
+   <property name="checkable">
+    <bool>true</bool>
+   </property>
+   <property name="text">
+    <string>Exclude region</string>
+   </property>
+  </action>
  </widget>
  <customwidgets>
   <customwidget>