diff --git a/invesalius/data/mask.py b/invesalius/data/mask.py
index 2212396..d0245b9 100644
--- a/invesalius/data/mask.py
+++ b/invesalius/data/mask.py
@@ -285,6 +285,26 @@ class Mask():
         shape = shape[0] + 1, shape[1] + 1, shape[2] + 1
         self.matrix = numpy.memmap(self.temp_file, mode='w+', dtype='uint8', shape=shape)
 
+    def copy(self, copy_name):
+        """
+        creates and return a copy from the mask instance.
+
+        params:
+            copy_name: the name from the copy
+        """
+        new_mask = Mask()
+        new_mask.name = copy_name
+        new_mask.colour = self.colour
+        new_mask.opacity = self.opacity
+        new_mask.threshold_range = self.threshold_range
+        new_mask.edition_threshold_range = self.edition_threshold_range
+        new_mask.is_shown = self.is_shown
+        
+        new_mask.create_mask(shape=[i-1 for i in self.matrix.shape])
+        new_mask.matrix[:] = self.matrix[:]
+
+        return new_mask
+
     def clear_history(self):
         self.history.clear_history()
 
diff --git a/invesalius/data/slice_.py b/invesalius/data/slice_.py
index 95be377..7fb0a24 100644
--- a/invesalius/data/slice_.py
+++ b/invesalius/data/slice_.py
@@ -224,14 +224,9 @@ class Slice(object):
             name = original_mask.name
             names_list = [mask_dict[i].name for i in mask_dict.keys()]
             new_name = utils.next_copy_name(name, names_list)
-            # create new mask
-            self.CreateMask(imagedata = original_mask.imagedata,
-                            name = new_name,
-                            colour = original_mask.colour,
-                            opacity = original_mask.opacity,
-                            threshold_range = original_mask.threshold_range,
-                            edition_threshold_range = original_mask.edition_threshold_range,
-                            edited_points = original_mask.edited_points)
+
+            copy_mask = original_mask.copy(new_name)
+            self._add_mask_into_proj(copy_mask)
 
     def OnEnableStyle(self, pubsub_evt):
         state = pubsub_evt.data
@@ -1090,22 +1085,32 @@ class Slice(object):
         if threshold_range:
             future_mask.threshold_range = threshold_range
 
-        # insert new mask into project and retrieve its index
+        self._add_mask_into_proj(future_mask)
+
+
+    def _add_mask_into_proj(self, mask, show=True):
+        """
+        Insert a new mask into project and retrieve its index.
+
+        Params:
+            mask: A mask object.
+            show: indicate if the mask will be shown.
+        """
         proj = Project()
-        index = proj.AddMask(future_mask)
-        future_mask.index = index
+        index = proj.AddMask(mask)
+        mask.index = index
 
         ## update gui related to mask
         Publisher.sendMessage('Add mask',
-                                    (future_mask.index,
-                                     future_mask.name,
-                                     future_mask.threshold_range,
-                                     future_mask.colour))
-
-        self.current_mask = future_mask
+                                    (mask.index,
+                                     mask.name,
+                                     mask.threshold_range,
+                                     mask.colour))
 
-        Publisher.sendMessage('Change mask selected', future_mask.index)
-        Publisher.sendMessage('Update slice viewer')
+        if show:
+            self.current_mask = mask
+            Publisher.sendMessage('Change mask selected', mask.index)
+            Publisher.sendMessage('Update slice viewer')
 
     def __load_masks(self, imagedata, mask_dict):
         keys = mask_dict.keys()
--
libgit2 0.21.2