diff --git a/Cura/gui/opengl.py b/Cura/gui/opengl.py
index c227600..bf89bf8 100644
--- a/Cura/gui/opengl.py
+++ b/Cura/gui/opengl.py
@@ -47,7 +47,7 @@ def InitGL(window, view3D, zoom):
 	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT)
 
 def DrawMachine(machineSize):
-	glColor3f(1,1,1)
+	glColor3f(1.0,1.0,1.0)
 	glLineWidth(4)
 	glDisable(GL_LIGHTING)
 	glBegin(GL_LINE_LOOP)
@@ -56,6 +56,7 @@ def DrawMachine(machineSize):
 	glVertex3f(machineSize.x, machineSize.y, 0)
 	glVertex3f(0, machineSize.y, 0)
 	glEnd()
+	glColor3f(0.7,0.7,0.7)
 	glLineWidth(2)
 	glBegin(GL_LINES)
 	for i in xrange(0, int(machineSize.x), 10):
@@ -203,7 +204,21 @@ def DrawBox(vMin, vMax):
 	glVertex3f(vMin[0], vMax[1], vMax[2])
 	glEnd()
 
-def DrawSTL(mesh):
+def DrawMeshOutline(mesh):
+	glEnable(GL_CULL_FACE)
+	glEnableClientState(GL_VERTEX_ARRAY);
+	glVertexPointer(3, GL_FLOAT, 0, mesh.vertexes)
+	
+	glCullFace(GL_FRONT)
+	glLineWidth(3)
+	glPolygonMode(GL_BACK, GL_LINE)
+	glDrawArrays(GL_TRIANGLES, 0, mesh.vertexCount)
+	glPolygonMode(GL_BACK, GL_FILL)
+	glCullFace(GL_BACK)
+	
+	glDisableClientState(GL_VERTEX_ARRAY)
+
+def DrawMesh(mesh):
 	glEnable(GL_CULL_FACE)
 	glEnableClientState(GL_VERTEX_ARRAY);
 	glEnableClientState(GL_NORMAL_ARRAY);
diff --git a/Cura/gui/preview3d.py b/Cura/gui/preview3d.py
index 27605a3..26ebe04 100644
--- a/Cura/gui/preview3d.py
+++ b/Cura/gui/preview3d.py
@@ -76,6 +76,9 @@ class previewPanel(wx.Panel):
 		toolbarUtil.RadioButton(self.toolbar, group, 'object-top-on.png', 'object-top-off.png', 'Topdown view', callback=self.OnTopClick)
 		self.toolbar.AddSeparator()
 
+		self.showBorderButton = toolbarUtil.ToggleButton(self.toolbar, '', 'view-border-on.png', 'view-border-off.png', 'Show model borders', callback=self.OnViewChange)
+		self.toolbar.AddSeparator()
+
 		group = []
 		self.normalViewButton = toolbarUtil.RadioButton(self.toolbar, group, 'view-normal-on.png', 'view-normal-off.png', 'Normal model view', callback=self.OnViewChange)
 		self.transparentViewButton = toolbarUtil.RadioButton(self.toolbar, group, 'view-transparent-on.png', 'view-transparent-off.png', 'Transparent model view', callback=self.OnViewChange)
@@ -331,6 +334,7 @@ class previewPanel(wx.Panel):
 			self.glCanvas.viewMode = "GCode"
 		elif self.mixedViewButton.GetValue():
 			self.glCanvas.viewMode = "Mixed"
+		self.glCanvas.drawBorders = self.showBorderButton.GetValue()
 		self.updateToolbar()
 		self.glCanvas.Refresh()
 	
@@ -533,7 +537,7 @@ class PreviewGLCanvas(glcanvas.GLCanvas):
 			if obj.dirty:
 				obj.dirty = False
 				glNewList(obj.displayList, GL_COMPILE)
-				opengl.DrawSTL(obj.mesh)
+				opengl.DrawMesh(obj.mesh)
 				glEndList()
 			
 			if self.viewMode == "Transparent" or self.viewMode == "Mixed":
@@ -593,11 +597,23 @@ class PreviewGLCanvas(glcanvas.GLCanvas):
 
 				glDisable(GL_STENCIL_TEST)
 				glEnable(GL_DEPTH_TEST)
+				
+				if self.drawBorders:
+					#Fix the depth buffer for the outline drawing.
+					glColorMask(GL_FALSE, GL_FALSE, GL_FALSE, GL_FALSE)
+					self.drawModel(obj)
+					glColorMask(GL_TRUE, GL_TRUE, GL_TRUE, GL_TRUE)
 			elif self.viewMode == "Normal":
 				glLightfv(GL_LIGHT0, GL_DIFFUSE, self.objColor[self.parent.objectList.index(obj)])
 				glLightfv(GL_LIGHT0, GL_AMBIENT, map(lambda x: x / 5, self.objColor[self.parent.objectList.index(obj)]))
 				glEnable(GL_LIGHTING)
 				self.drawModel(obj)
+			
+			if self.drawBorders and (self.viewMode == "Normal" or self.viewMode == "Transparent" or self.viewMode == "X-Ray"):
+				glEnable(GL_DEPTH_TEST)
+				glDisable(GL_LIGHTING)
+				glColor3f(1,1,1)
+				opengl.DrawMeshOutline(obj.mesh)
 		
 		glPopMatrix()	
 		if self.viewMode == "Normal" or self.viewMode == "Transparent" or self.viewMode == "X-Ray":
diff --git a/Cura/gui/toolbarUtil.py b/Cura/gui/toolbarUtil.py
index e49d77c..64dc984 100644
--- a/Cura/gui/toolbarUtil.py
+++ b/Cura/gui/toolbarUtil.py
@@ -94,6 +94,8 @@ class ToggleButton(buttons.GenBitmapToggleButton):
 
 	def OnButton(self, event):
 		self.SetBitmap(self.GetValue())
+		if self.callback != None:
+			self.callback()
 		event.Skip()
 
 	def OnButtonProfile(self, event):
@@ -103,7 +105,8 @@ class ToggleButton(buttons.GenBitmapToggleButton):
 		else:
 			self.SetBitmap(False)
 			profile.putProfileSetting(self.profileSetting, 'False')
-		self.callback()
+		if self.callback != None:
+			self.callback()
 		event.Skip()
 
 	def OnMouseEnter(self, event):
diff --git a/Cura/images/view-border-off.png b/Cura/images/view-border-off.png
new file mode 100644
index 0000000..3019205
Binary files /dev/null and b/Cura/images/view-border-off.png differ
diff --git a/Cura/images/view-border-on.png b/Cura/images/view-border-on.png
new file mode 100644
index 0000000..2d27e29
Binary files /dev/null and b/Cura/images/view-border-on.png differ