diff --git a/PyLoT.py b/PyLoT.py
index 4a8ba360..b3a40aa1 100755
--- a/PyLoT.py
+++ b/PyLoT.py
@@ -2039,10 +2039,11 @@ class MainWindow(QMainWindow):
         self.update_obspy_dmt()
 
     def update_obspy_dmt(self):
+        self.metadata.clear_inventory()
         if self.obspy_dmt:
             invpath = os.path.join(self.get_current_event_path(), 'resp')
             if not invpath in self.metadata.inventories:
-                self.metadata.add_inventory(invpath)
+                self.metadata.add_inventory(invpath, obspy_dmt_inv = True)
             # check if directory is empty
             if os.listdir(invpath):
                 self.init_map_button.setEnabled(True)
@@ -3527,6 +3528,7 @@ class MainWindow(QMainWindow):
         '''
         Save back project to new pickle file.
         '''
+        self.metadata.clear_inventory()
         dlg = QFileDialog(self)
         fnm = dlg.getSaveFileName(self, 'Create a new project file...', filter='Pylot project (*.plp)')
         filename = fnm[0]
@@ -3541,6 +3543,7 @@ class MainWindow(QMainWindow):
         self.saveProjectAsAction.setEnabled(True)
         self.update_status('Saved new project to {}'.format(filename), duration=5000)
         self.add2recentProjects(filename)
+        self.update_obspy_dmt()
         return True
 
     def saveProject(self, new=False):
@@ -3553,9 +3556,11 @@ class MainWindow(QMainWindow):
                     self.setDirty(True)
                     return False
             else:
+                self.metadata.clear_inventory()
                 self.project.parameter = self._inputs
                 self.exportEvents()
                 self.project.save()
+                self.update_obspy_dmt()
             if not self.project.dirty:
                 self.setDirty(False)
                 self.update_status('Saved back project to file:\n{}'.format(self.project.location), duration=5000)
diff --git a/pylot/core/util/dataprocessing.py b/pylot/core/util/dataprocessing.py
index 9ada2df9..3eb2007f 100644
--- a/pylot/core/util/dataprocessing.py
+++ b/pylot/core/util/dataprocessing.py
@@ -22,6 +22,8 @@ class Metadata(object):
         # seed id as key, path to file as value
         self.seed_ids = {}
         self.stations_dict = {}
+        # saves which metadata files are from obspy dmt
+        self.obspy_dmt_invs = []
         if inventory:
             if os.path.isdir(inventory):
                 self.add_inventory(inventory)
@@ -44,7 +46,7 @@ class Metadata(object):
     def __repr__(self):
         return self.__str__()
 
-    def add_inventory(self, path_to_inventory):
+    def add_inventory(self, path_to_inventory, obspy_dmt_inv = False):
         """
         Add path to list of inventories.
         :param path_to_inventory: Path to a folder
@@ -54,6 +56,8 @@ class Metadata(object):
         assert (os.path.isdir(path_to_inventory)), '{} is no directory'.format(path_to_inventory)
         if path_to_inventory not in self.inventories:
             self.inventories.append(path_to_inventory)
+        if obspy_dmt_inv == True:
+            self.obspy_dmt_invs.append(path_to_inventory)
 
     def add_inventory_file(self, path_to_inventory_file):
         """
@@ -89,6 +93,11 @@ class Metadata(object):
         # this will be rebuilt for the next init of the arraymap anyway, so just reset it
         self.stations_dict = {}
 
+    def clear_inventory(self):
+        for inv in self.obspy_dmt_invs:
+            self.remove_inventory(inv)
+        self.obspy_dmt_invs = []
+
     def get_metadata(self, seed_id, time=None):
         """
         Get metadata for seed id at time. When time is not specified, metadata for current time is fetched.
diff --git a/pylot/core/util/widgets.py b/pylot/core/util/widgets.py
index 7af88575..32717f60 100644
--- a/pylot/core/util/widgets.py
+++ b/pylot/core/util/widgets.py
@@ -206,7 +206,7 @@ class AddMetadataWidget(QWidget):
     def init_add_remove_buttons(self):
         self.add_remove_layout = QVBoxLayout()
         self.add_button = self.init_button("Add", Qt.Key_Insert, "Choose a file to add \n(Ins)")
-        self.remove_button = self.init_button("Remove", Qt.Key_Delete, "Remove selected file \n(Del)")
+        self.remove_button = self.init_button("Remove", Qt.Key_Delete, "Remove selected file(s) \n(Del)")
         self.add_remove_layout.addWidget(self.add_button, 0, QtCore.Qt.AlignBottom)
         self.add_remove_layout.addWidget(self.remove_button, 0, QtCore.Qt.AlignTop)
         self.list_buttons_layout.insertLayout(1, self.add_remove_layout, 0)
@@ -252,6 +252,8 @@ class AddMetadataWidget(QWidget):
         for inventory_path in self.metadata.inventories:
             item = QtGui.QStandardItem(inventory_path)
             self.list_model.appendRow(item)
+            if inventory_path in self.metadata.obspy_dmt_invs:
+                item.setFlags(Qt.NoItemFlags)
 
     def directory_to_lineedit(self):
         inventory_path = self.open_directory()