diff --git a/CHANGELOG.md b/CHANGELOG.md
index 09998d82..f6faf07e 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -7,6 +7,10 @@ CHANGELOG for FlatCAM beta
 
 =================================================
 
+01.05.2020
+
+- added some ToolTips (strings needed to be translated too) for the Cut Z entry in Geometry Object UI that explain why is sometime disabled and reason for it's value (sometime is zero)
+
 30.04.2020 
 
 - made some corrections - due of recent refactoring PyCharm reported errors all over (not correct but it made programming difficult)
diff --git a/camlib.py b/camlib.py
index da0854f9..f4dff415 100644
--- a/camlib.py
+++ b/camlib.py
@@ -3472,8 +3472,7 @@ class CNCjob(Geometry):
                     else:
                         log.debug("camlib.CNCJob.generate_from_excellon_by_tool() --> "
                                   "The loaded Excellon file has no drills ...")
-                        self.app.inform.emit('[ERROR_NOTCL] %s...' %
-                                             _('The loaded Excellon file has no drills'))
+                        self.app.inform.emit('[ERROR_NOTCL] %s...' % _('The loaded Excellon file has no drills'))
                         return 'fail'
                 self.z_cut = deepcopy(old_zcut)
             log.debug("The total travel distance with Travelling Salesman Algorithm is: %s" % str(measured_distance))
@@ -3499,14 +3498,12 @@ class CNCjob(Geometry):
         self.app.inform.emit(_("Finished G-Code generation..."))
         return 'OK'
 
-    def generate_from_multitool_geometry(
-            self, geometry, append=True,
-            tooldia=None, offset=0.0, tolerance=0, z_cut=1.0, z_move=2.0,
-            feedrate=2.0, feedrate_z=2.0, feedrate_rapid=30,
-            spindlespeed=None, spindledir='CW', dwell=False, dwelltime=1.0,
-            multidepth=False, depthpercut=None,
-            toolchange=False, toolchangez=1.0, toolchangexy="0.0, 0.0", extracut=False, extracut_length=0.2,
-            startz=None, endz=2.0, endxy='', pp_geometry_name=None, tool_no=1):
+    def generate_from_multitool_geometry(self, geometry, append=True, tooldia=None, offset=0.0, tolerance=0, z_cut=1.0,
+                                         z_move=2.0, feedrate=2.0, feedrate_z=2.0, feedrate_rapid=30,
+                                         spindlespeed=None, spindledir='CW', dwell=False, dwelltime=1.0,
+                                         multidepth=False, depthpercut=None, toolchange=False, toolchangez=1.0,
+                                         toolchangexy="0.0, 0.0", extracut=False, extracut_length=0.2,
+                                         startz=None, endz=2.0, endxy='', pp_geometry_name=None, tool_no=1):
         """
         Algorithm to generate from multitool Geometry.
 
@@ -5025,8 +5022,7 @@ class CNCjob(Geometry):
 
         return path
 
-    def linear2gcode(self, linear, tolerance=0, down=True, up=True,
-                     z_cut=None, z_move=None, zdownrate=None,
+    def linear2gcode(self, linear, tolerance=0, down=True, up=True, z_cut=None, z_move=None, zdownrate=None,
                      feedrate=None, feedrate_z=None, feedrate_rapid=None, cont=False, old_point=(0, 0)):
         """
 
@@ -5119,8 +5115,7 @@ class CNCjob(Geometry):
                 # For Incremental coordinates type G91
                 # next_x = pt[0] - prev_x
                 # next_y = pt[1] - prev_y
-                self.app.inform.emit('[ERROR_NOTCL] %s' %
-                                     _('G91 coordinates not implemented ...'))
+                self.app.inform.emit('[ERROR_NOTCL] %s' % _('G91 coordinates not implemented ...'))
                 next_x = pt[0]
                 next_y = pt[1]
 
diff --git a/flatcamObjects/FlatCAMGeometry.py b/flatcamObjects/FlatCAMGeometry.py
index e18bd96e..cf70054c 100644
--- a/flatcamObjects/FlatCAMGeometry.py
+++ b/flatcamObjects/FlatCAMGeometry.py
@@ -1114,6 +1114,26 @@ class GeometryObject(FlatCAMObj, Geometry):
             self.ui.tipanglelabel.show()
             self.ui.tipangle_entry.show()
             self.ui.cutz_entry.setDisabled(True)
+            self.ui.cutzlabel.setToolTip(
+                _("Disabled because the tool is V-shape.\n"
+                  "For V-shape tools the depth of cut is\n"
+                  "calculated from other parameters like:\n"
+                  "- 'V-tip Angle' -> angle at the tip of the tool\n"
+                  "- 'V-tip Dia' -> diameter at the tip of the tool \n"
+                  "- Tool Dia -> 'Dia' column found in the Tool Table\n"
+                  "NB: a value of zero means that Tool Dia = 'V-tip Dia'"
+                )
+            )
+            self.ui.cutz_entry.setToolTip(
+                _("Disabled because the tool is V-shape.\n"
+                  "For V-shape tools the depth of cut is\n"
+                  "calculated from other parameters like:\n"
+                  "- 'V-tip Angle' -> angle at the tip of the tool\n"
+                  "- 'V-tip Dia' -> diameter at the tip of the tool \n"
+                  "- Tool Dia -> 'Dia' column found in the Tool Table\n"
+                  "NB: a value of zero means that Tool Dia = 'V-tip Dia'"
+                  )
+            )
 
             self.update_cutz()
         else:
@@ -1122,6 +1142,12 @@ class GeometryObject(FlatCAMObj, Geometry):
             self.ui.tipanglelabel.hide()
             self.ui.tipangle_entry.hide()
             self.ui.cutz_entry.setDisabled(False)
+            self.ui.cutzlabel.setToolTip(
+                _("Cutting depth (negative)\n"
+                  "below the copper surface."
+                )
+            )
+            self.ui.cutz_entry.setToolTip('')
 
     def update_cutz(self):
         vdia = float(self.ui.tipdia_entry.get_value())