diff --git a/invesalius/data/slice_.py b/invesalius/data/slice_.py
index 16b18ef..11b274d 100644
--- a/invesalius/data/slice_.py
+++ b/invesalius/data/slice_.py
@@ -93,7 +93,9 @@ class Slice(object):
 
         ps.Publisher().subscribe(self.OnEnableStyle, 'Enable style')
         ps.Publisher().subscribe(self.OnDisableStyle, 'Disable style')
+
         ps.Publisher().subscribe(self.OnRemoveMasks, 'Remove masks')
+        ps.Publisher().subscribe(self.OnDuplicateMasks, 'Duplicate masks')
 
 
     def OnRemoveMasks(self, pubsub_evt):
@@ -110,6 +112,25 @@ class Slice(object):
             self.blend_filter.Update()
             ps.Publisher().sendMessage('Update slice viewer')
 
+    def OnDuplicateMasks(self, pubsub_evt):
+        selected_items = pubsub_evt.data
+        proj = Project()
+        mask_dict = proj.mask_dict
+        for index in selected_items:
+            original_mask = mask_dict[index]
+            # compute copy name
+            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)
+
 
     def OnEnableStyle(self, pubsub_evt):
         state = pubsub_evt.data
@@ -538,18 +559,28 @@ class Slice(object):
         
         widget.SetInput(flip.GetOutput())
  
-    
-    def CreateMask(self, imagedata=None, name=None):
+
+    def CreateMask(self, imagedata=None, name=None, colour=None,
+                    opacity=None, threshold_range=None,
+                    edition_threshold_range = None,
+                    edited_points=None):
 
         future_mask = Mask()
+        if colour:
+            future_mask.colour = colour
+        if opacity:
+            future_mask.opacity = opacity
+        if threshold_range:
+            future_mask.threshold_range = threshold_range
+        if edition_threshold_range:
+            future_mask.edition_threshold_range = edition_threshold_range
+        if edited_points:
+            future_mask.edited_points = edited_points
 
         # this is not the first mask, so we will import data from old imagedata
         if imagedata is None:
-
             old_mask = self.current_mask
-
             imagedata = old_mask.imagedata
-
             future_mask.threshold_range = old_mask.threshold_range
 
         # if not defined in the method call, this will have been computed on
diff --git a/invesalius/gui/data_notebook.py b/invesalius/gui/data_notebook.py
index eb7499d..ab4d1e8 100644
--- a/invesalius/gui/data_notebook.py
+++ b/invesalius/gui/data_notebook.py
@@ -70,12 +70,12 @@ class MaskPage(wx.Panel):
     """
     def __init__(self, parent):
         wx.Panel.__init__(self, parent, pos=wx.Point(0, 50),
-                            size=wx.Size(256, 120))
+                            size=wx.Size(256, 140))
         self.__init_gui()
 
     def __init_gui(self):
         # listctrl were existing masks will be listed
-        self.listctrl = MasksListCtrlPanel(self, size=wx.Size(256, 80))
+        self.listctrl = MasksListCtrlPanel(self, size=wx.Size(256, 100))
         # button control with tools (eg. remove, add new, etc)
         self.buttonctrl = ButtonControlPanel(self)
 
@@ -93,7 +93,7 @@ class ButtonControlPanel(wx.Panel):
     """
     def __init__(self, parent):
         wx.Panel.__init__(self, parent, pos=wx.Point(0, 50),
-                            size=wx.Size(256, 20))
+                            size=wx.Size(256, 22))
         self.parent = parent
         self.__init_gui()
 
@@ -111,13 +111,16 @@ class ButtonControlPanel(wx.Panel):
         button_style = pbtn.PB_STYLE_SQUARE | pbtn.PB_STYLE_DEFAULT
         button_new = pbtn.PlateButton(self, BTN_NEW, "",
                                      BMP_NEW,
-                                     style=button_style)
+                                     style=button_style,
+                                     size = wx.Size(18, 18))
         button_remove = pbtn.PlateButton(self, BTN_REMOVE, "",
                                          BMP_REMOVE,
-                                         style=button_style)
+                                         style=button_style,
+                                         size = wx.Size(18, 18))
         button_duplicate = pbtn.PlateButton(self, BTN_DUPLICATE, "",
                                             BMP_DUPLICATE,
-                                            style=button_style)
+                                            style=button_style,
+                                            size = wx.Size(18, 18))
 
         # Add all controls to gui
         sizer = wx.BoxSizer(wx.HORIZONTAL)
diff --git a/invesalius/gui/default_tasks.py b/invesalius/gui/default_tasks.py
index 8d388a4..526689e 100755
--- a/invesalius/gui/default_tasks.py
+++ b/invesalius/gui/default_tasks.py
@@ -111,7 +111,7 @@ class LowerTaskPanel(wx.Panel):
     def __init__(self, parent):
         wx.Panel.__init__(self, parent, pos=wx.Point(5, 5),
         #                  size=wx.Size(280, 700))
-                           size=wx.Size(280, 400))
+                           size=wx.Size(280, 420))
         
         fold_panel = fpb.FoldPanelBar(self, -1, wx.DefaultPosition,
                                       self.GetSize(),fpb.FPB_DEFAULT_STYLE,
--
libgit2 0.21.2