diff --git a/Modules/QtWidgets/include/QmitkRenderWindowWidget.h b/Modules/QtWidgets/include/QmitkRenderWindowWidget.h
index 0638162cd2..ec6bcb8879 100644
--- a/Modules/QtWidgets/include/QmitkRenderWindowWidget.h
+++ b/Modules/QtWidgets/include/QmitkRenderWindowWidget.h
@@ -1,110 +1,110 @@
 /*===================================================================
 
 The Medical Imaging Interaction Toolkit (MITK)
 
 Copyright (c) German Cancer Research Center,
 Division of Medical Image Computing.
 All rights reserved.
 
 This software is distributed WITHOUT ANY WARRANTY; without
 even the implied warranty of MERCHANTABILITY or FITNESS FOR
 A PARTICULAR PURPOSE.
 
 See LICENSE.txt or http://www.mitk.org for details.
 
 ===================================================================*/
 
 #ifndef QMITKRENDERWINDOWWIDGET_H
 #define QMITKRENDERWINDOWWIDGET_H
 
 // qt widgets module
 #include "MitkQtWidgetsExports.h"
 #include "QmitkRenderWindow.h"
 
 // mitk core
 #include <mitkDataStorage.h>
 #include <mitkPointSet.h>
 #include <mitkRenderWindow.h>
 #include <vtkCornerAnnotation.h>
 
 // qt
 #include <QWidget>
 #include <QHBoxLayout>
 
 /**
-* @brief The 'QmitkRenderWindowWidget' is a QWidget that holds a render window
+* @brief The 'QmitkRenderWindowWidget' is a QFrame that holds a render window
 *        and some associates properties, like a crosshair (pointset) and decorations.
 *        Decorations are corner annotation (text and color) or background color and can be set using this class.
 *        The 'QmitkRenderWindowWidget' is used inside the 'QmitkMxNMultiWidget', where a map contains
 *        several render window widgets to create the MxN display.
 */
-class MITKQTWIDGETS_EXPORT QmitkRenderWindowWidget : public QWidget
+class MITKQTWIDGETS_EXPORT QmitkRenderWindowWidget : public QFrame
 {
   Q_OBJECT
 
 public:
 
   QmitkRenderWindowWidget(
     QWidget* parent = nullptr,
     const QString& widgetName = "",
     mitk::DataStorage* dataStorage = nullptr,
     mitk::BaseRenderer::RenderingMode::Type renderingMode = mitk::BaseRenderer::RenderingMode::Standard
   );
 
   virtual ~QmitkRenderWindowWidget();
 
   void SetDataStorage(mitk::DataStorage* dataStorage);
 
   const QString& GetWidgetName() const { return m_WidgetName; };
   QmitkRenderWindow* GetRenderWindow() const { return m_RenderWindow; };
 
   mitk::SliceNavigationController* GetSliceNavigationController() const;
 
   void RequestUpdate();
   void ForceImmediateUpdate();
 
   void SetGradientBackgroundColors(const mitk::Color& upper, const mitk::Color& lower);
   void ShowGradientBackground(bool enable);
   std::pair<mitk::Color, mitk::Color> GetGradientBackgroundColors() const { return m_GradientBackgroundColors; };
   bool IsGradientBackgroundOn() const;
 
   void SetDecorationColor(const mitk::Color& color);
   mitk::Color GetDecorationColor() const { return m_DecorationColor; };
 
   void ShowColoredRectangle(bool show);
   bool IsColoredRectangleVisible() const;
 
   void ShowCornerAnnotation(bool show);
   bool IsCornerAnnotationVisible() const;
   void SetCornerAnnotationText(const std::string& cornerAnnotation);
   std::string GetCornerAnnotationText() const;
 
   bool IsRenderWindowMenuActivated() const;
 
   void ActivateCrosshair(bool activate);
 
 private:
 
   void InitializeGUI();
   void InitializeDecorations();
 
   void SetCrosshair(mitk::Point3D selectedPoint);
 
   QString m_WidgetName;
   QHBoxLayout* m_Layout;
 
   mitk::DataStorage* m_DataStorage;
   QmitkRenderWindow* m_RenderWindow;
 
   mitk::RenderingManager::Pointer m_RenderingManager;
   mitk::BaseRenderer::RenderingMode::Type m_RenderingMode;
 
   mitk::DataNode::Pointer m_PointSetNode;
   mitk::PointSet::Pointer m_PointSet;
 
   std::pair<mitk::Color, mitk::Color> m_GradientBackgroundColors;
   mitk::Color m_DecorationColor;
   vtkSmartPointer<vtkCornerAnnotation> m_CornerAnnotation;
 };
 
 #endif // QMITKRENDERWINDOWWIDGET_H
diff --git a/Modules/QtWidgets/src/QmitkRenderWindowWidget.cpp b/Modules/QtWidgets/src/QmitkRenderWindowWidget.cpp
index e5f6376413..2584006ec6 100644
--- a/Modules/QtWidgets/src/QmitkRenderWindowWidget.cpp
+++ b/Modules/QtWidgets/src/QmitkRenderWindowWidget.cpp
@@ -1,243 +1,245 @@
 /*===================================================================
 
 The Medical Imaging Interaction Toolkit (MITK)
 
 Copyright (c) German Cancer Research Center,
 Division of Medical Image Computing.
 All rights reserved.
 
 This software is distributed WITHOUT ANY WARRANTY; without
 even the implied warranty of MERCHANTABILITY or FITNESS FOR
 A PARTICULAR PURPOSE.
 
 See LICENSE.txt or http://www.mitk.org for details.
 
 ===================================================================*/
 
 #include "QmitkRenderWindowWidget.h"
 
 // mitk qt widgets
 #include <QmitkMxNMultiWidget.h>
 
 // vtk
 #include <vtkTextProperty.h>
 
 QmitkRenderWindowWidget::QmitkRenderWindowWidget(QWidget* parent/* = nullptr*/,
                                                  const QString& widgetName/* = ""*/,
                                                  mitk::DataStorage* dataStorage/* = nullptr*/,
                                                  mitk::BaseRenderer::RenderingMode::Type renderingMode/* = mitk::BaseRenderer::RenderingMode::Standard*/)
-  : QWidget(parent)
+  : QFrame(parent)
   , m_WidgetName(widgetName)
   , m_DataStorage(dataStorage)
   , m_RenderWindow(nullptr)
   , m_RenderingMode(renderingMode)
   , m_PointSetNode(nullptr)
   , m_PointSet(nullptr)
 {
   InitializeGUI();
 }
 
 QmitkRenderWindowWidget::~QmitkRenderWindowWidget()
 {
   auto sliceNavigationController = m_RenderWindow->GetSliceNavigationController();
   if (nullptr != sliceNavigationController)
   {
     sliceNavigationController->SetCrosshairEvent.RemoveListener(mitk::MessageDelegate1<QmitkRenderWindowWidget, mitk::Point3D>(this, &QmitkRenderWindowWidget::SetCrosshair));
   }
   if (nullptr != m_DataStorage)
   {
     m_DataStorage->Remove(m_PointSetNode);
   }
 }
 
 void QmitkRenderWindowWidget::SetDataStorage(mitk::DataStorage* dataStorage)
 {
   if (dataStorage == m_DataStorage)
   {
     return;
   }
 
   m_DataStorage = dataStorage;
   if (nullptr != m_RenderWindow)
   {
     mitk::BaseRenderer::GetInstance(m_RenderWindow->GetRenderWindow())->SetDataStorage(dataStorage);
   }
 }
 
 mitk::SliceNavigationController* QmitkRenderWindowWidget::GetSliceNavigationController() const
 {
   return m_RenderWindow->GetSliceNavigationController();
 }
 
 void QmitkRenderWindowWidget::RequestUpdate()
 {
   m_RenderingManager->RequestUpdate(m_RenderWindow->GetRenderWindow());
 }
 
 void QmitkRenderWindowWidget::ForceImmediateUpdate()
 {
   m_RenderingManager->ForceImmediateUpdate(m_RenderWindow->GetRenderWindow());
 }
 
 void QmitkRenderWindowWidget::SetGradientBackgroundColors(const mitk::Color& upper, const mitk::Color& lower)
 {
   vtkRenderer* vtkRenderer = m_RenderWindow->GetRenderer()->GetVtkRenderer();
   if (nullptr == vtkRenderer)
   {
     return;
   }
 
   m_GradientBackgroundColors.first = upper;
   m_GradientBackgroundColors.second = lower;
   vtkRenderer->SetBackground(lower[0], lower[1], lower[2]);
   vtkRenderer->SetBackground2(upper[0], upper[1], upper[2]);
 
   ShowGradientBackground(true);
 }
 
 void QmitkRenderWindowWidget::ShowGradientBackground(bool show)
 {
   m_RenderWindow->GetRenderer()->GetVtkRenderer()->SetGradientBackground(show);
 }
 
 bool QmitkRenderWindowWidget::IsGradientBackgroundOn() const
 {
   return m_RenderWindow->GetRenderer()->GetVtkRenderer()->GetGradientBackground();
 }
 
 void QmitkRenderWindowWidget::SetDecorationColor(const mitk::Color& color)
 {
   m_DecorationColor = color;
   m_CornerAnnotation->GetTextProperty()->SetColor(color[0], color[1], color[2]);
 }
 
 void QmitkRenderWindowWidget::ShowColoredRectangle(bool show)
 {
   // Not implemented for now. Colored rectangle is defined via qt border stylesheet
 }
 
 bool QmitkRenderWindowWidget::IsColoredRectangleVisible() const
 {
   return false;
 }
 
 void QmitkRenderWindowWidget::ShowCornerAnnotation(bool show)
 {
   m_CornerAnnotation->SetVisibility(show);
 }
 
 bool QmitkRenderWindowWidget::IsCornerAnnotationVisible() const
 {
   return m_CornerAnnotation->GetVisibility() > 0;
 }
 
 void QmitkRenderWindowWidget::SetCornerAnnotationText(const std::string& cornerAnnotation)
 {
   m_CornerAnnotation->SetText(0, cornerAnnotation.c_str());
 }
 
 std::string QmitkRenderWindowWidget::GetCornerAnnotationText() const
 {
   return std::string(m_CornerAnnotation->GetText(0));
 }
 
 bool QmitkRenderWindowWidget::IsRenderWindowMenuActivated() const
 {
   return m_RenderWindow->GetActivateMenuWidgetFlag();
 }
 
 void QmitkRenderWindowWidget::ActivateCrosshair(bool activate)
 {
   if (nullptr == m_DataStorage)
   {
     return;
   }
 
   if (activate)
   {
     try
     {
       m_DataStorage->Add(m_PointSetNode);
     }
     catch(std::invalid_argument& /*e*/)
     {
       // crosshair already existing
       return;
     }
   }
   else
   {
     m_DataStorage->Remove(m_PointSetNode);
   }
 }
 
 void QmitkRenderWindowWidget::InitializeGUI()
 {
   m_Layout = new QHBoxLayout(this);
   m_Layout->setMargin(0);
   setLayout(m_Layout);
   setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Expanding);
 
   // create render window for this render window widget
   m_RenderingManager = mitk::RenderingManager::GetInstance();
   //m_RenderingManager = mitk::RenderingManager::New();
   m_RenderingManager->SetDataStorage(m_DataStorage);
 
   m_RenderWindow = new QmitkRenderWindow(this, m_WidgetName, nullptr, m_RenderingManager, m_RenderingMode);
   m_RenderWindow->SetLayoutIndex(mitk::SliceNavigationController::Sagittal);
   m_RenderWindow->GetSliceNavigationController()->SetDefaultViewDirection(mitk::SliceNavigationController::Sagittal);
   m_RenderWindow->GetSliceNavigationController()->SetRenderingManager(m_RenderingManager);
   m_RenderWindow->GetSliceNavigationController()->SetCrosshairEvent.AddListener(mitk::MessageDelegate1<QmitkRenderWindowWidget, mitk::Point3D>(this, &QmitkRenderWindowWidget::SetCrosshair));
 
   mitk::TimeGeometry::ConstPointer timeGeometry = m_DataStorage->ComputeBoundingGeometry3D(m_DataStorage->GetAll());
   m_RenderingManager->InitializeViews(timeGeometry);
   m_Layout->addWidget(m_RenderWindow);
 
   // add point set as a crosshair
   m_PointSetNode = mitk::DataNode::New();
   m_PointSetNode->SetProperty("name", mitk::StringProperty::New("Crosshair of render window " + m_WidgetName.toStdString()));
   m_PointSetNode->SetProperty("helper object", mitk::BoolProperty::New(true)); // crosshair-node should typically be invisible
 
   // set the crosshair only visible for this specific renderer
   m_PointSetNode->SetBoolProperty("fixedLayer", true, m_RenderWindow->GetRenderer());
   m_PointSetNode->SetVisibility(true, m_RenderWindow->GetRenderer());
   m_PointSetNode->SetVisibility(false);
 
   m_PointSet = mitk::PointSet::New();
   m_PointSetNode->SetData(m_PointSet);
 
   // set colors and corner annotation
   InitializeDecorations();
 }
 
 void QmitkRenderWindowWidget::InitializeDecorations()
 {
   vtkRenderer* vtkRenderer = m_RenderWindow->GetRenderer()->GetVtkRenderer();
   if (nullptr == vtkRenderer)
   {
     return;
   }
 
   // initialize background color gradients
   float black[3] = { 0.0f, 0.0f, 0.0f };
   SetGradientBackgroundColors(black, black);
 
   // initialize decoration color, rectangle and annotation text
   float white[3] = { 1.0f, 1.0f, 1.0f };
   m_DecorationColor = white;
 
+  setStyleSheet("border: 2px solid white");
+
   m_CornerAnnotation = vtkSmartPointer<vtkCornerAnnotation>::New();
   m_CornerAnnotation->SetText(0, "Sagittal");
   m_CornerAnnotation->SetMaximumFontSize(12);
   m_CornerAnnotation->GetTextProperty()->SetColor(m_DecorationColor[0], m_DecorationColor[1], m_DecorationColor[2]);
   if (0 == vtkRenderer->HasViewProp(m_CornerAnnotation))
   {
     vtkRenderer->AddViewProp(m_CornerAnnotation);
   }
 }
 
 void QmitkRenderWindowWidget::SetCrosshair(mitk::Point3D selectedPoint)
 {
   m_PointSet->SetPoint(1, selectedPoint, 0);
   mitk::RenderingManager::GetInstance()->RequestUpdate(m_RenderWindow->GetRenderWindow());
 }