diff --git a/src/adaptors/UBSvgSubsetAdaptor.cpp b/src/adaptors/UBSvgSubsetAdaptor.cpp
index cdaea1e2..660a2f5a 100644
--- a/src/adaptors/UBSvgSubsetAdaptor.cpp
+++ b/src/adaptors/UBSvgSubsetAdaptor.cpp
@@ -29,6 +29,7 @@
 #include "domain/UBGraphicsTextItem.h"
 #include "domain/UBAbstractWidget.h"
 #include "domain/UBGraphicsStroke.h"
+#include "domain/UBItem.h"
 
 #include "tools/UBGraphicsRuler.h"
 #include "tools/UBGraphicsCompass.h"
@@ -1337,11 +1338,13 @@ UBGraphicsPolygonItem* UBSvgSubsetAdaptor::UBSvgSubsetReader::polygonItemFromPol
 
     if (!ubZValue.isNull())
     {
-        polygonItem->setZValue(ubZValue.toString().toFloat());
+//        polygonItem->setZValue (ubZValue.toString().toFloat());
+        UBGraphicsItem::assignZValue(polygonItem, ubZValue.toString().toFloat());
     }
     else
     {
-        polygonItem->setZValue(mGroupZIndex);
+//        polygonItem->setZValue(mGroupZIndex);
+        UBGraphicsItem::assignZValue(polygonItem, mGroupZIndex);
     }
 
     QStringRef ubFillOnDarkBackground = mXmlReader.attributes().value(mNamespaceUri, "fill-on-dark-background");
@@ -1444,11 +1447,13 @@ UBGraphicsPolygonItem* UBSvgSubsetAdaptor::UBSvgSubsetReader::polygonItemFromLin
 
     if (!ubZValue.isNull())
     {
-        polygonItem->setZValue(ubZValue.toString().toFloat());
+//        polygonItem->setZValue(ubZValue.toString().toFloat());
+        UBGraphicsItem::assignZValue(polygonItem, ubZValue.toString().toFloat());
     }
     else
     {
-        polygonItem->setZValue(mGroupZIndex);
+//        polygonItem->setZValue(mGroupZIndex);
+        UBGraphicsItem::assignZValue(polygonItem, mGroupZIndex);
     }
 
 
@@ -1587,7 +1592,8 @@ QList<UBGraphicsPolygonItem*> UBSvgSubsetAdaptor::UBSvgSubsetReader::polygonItem
         {
             UBGraphicsPolygonItem* polygonItem = new UBGraphicsPolygonItem(QLineF(points.at(i), points.at(i + 1)), lineWidth);
             polygonItem->setColor(brushColor);
-            polygonItem->setZValue(zValue);
+//            polygonItem->setZValue(zValue);
+            UBGraphicsItem::assignZValue(polygonItem, zValue);
             polygonItem->setColorOnDarkBackground(colorOnDarkBackground);
             polygonItem->setColorOnLightBackground(colorOnLightBackground);
 
@@ -1931,7 +1937,8 @@ void UBSvgSubsetAdaptor::UBSvgSubsetReader::graphicsItemFromSvg(QGraphicsItem* g
 
     if (!ubZValue.isNull())
     {
-        gItem->setZValue(ubZValue.toString().toFloat());
+//        gItem->setZValue(ubZValue.toString().toFloat());
+        UBGraphicsItem::assignZValue(gItem, ubZValue.toString().toFloat());
     }
 
     UBItem* ubItem = dynamic_cast<UBItem*>(gItem);
@@ -2484,7 +2491,8 @@ UBGraphicsRuler* UBSvgSubsetAdaptor::UBSvgSubsetReader::rulerFromSvg()
 
     graphicsItemFromSvg(ruler);
 
-    ruler->setZValue(UBGraphicsScene::toolLayerStart + UBGraphicsScene::toolOffsetRuler);
+//    ruler->setZValue(UBGraphicsScene::toolLayerStart + UBGraphicsScene::toolOffsetRuler);
+    UBGraphicsItem::assignZValue(ruler, UBGraphicsScene::toolLayerStart + UBGraphicsScene::toolOffsetRuler);
     ruler->setData(UBGraphicsItemData::ItemLayerType, QVariant(UBItemLayerType::Tool));
 
     QStringRef svgWidth = mXmlReader.attributes().value("width");
@@ -2542,7 +2550,8 @@ UBGraphicsCompass* UBSvgSubsetAdaptor::UBSvgSubsetReader::compassFromSvg()
 
     graphicsItemFromSvg(compass);
 
-    compass->setZValue(UBGraphicsScene::toolLayerStart + UBGraphicsScene::toolOffsetCompass);
+    //compass->setZValue(UBGraphicsScene::toolLayerStart + UBGraphicsScene::toolOffsetCompass);
+    UBGraphicsItem::assignZValue(compass, UBGraphicsScene::toolLayerStart + UBGraphicsScene::toolOffsetCompass);
     compass->setData(UBGraphicsItemData::ItemLayerType, QVariant(UBItemLayerType::Tool));
 
     QStringRef svgX = mXmlReader.attributes().value("x");
@@ -2606,7 +2615,8 @@ UBGraphicsProtractor* UBSvgSubsetAdaptor::UBSvgSubsetReader::protractorFromSvg()
 {
     UBGraphicsProtractor* protractor = new UBGraphicsProtractor();
 
-    protractor->setZValue(UBGraphicsScene::toolLayerStart + UBGraphicsScene::toolOffsetProtractor);
+//    protractor->setZValue(UBGraphicsScene::toolLayerStart + UBGraphicsScene::toolOffsetProtractor);
+    UBGraphicsItem::assignZValue(protractor, UBGraphicsScene::toolLayerStart + UBGraphicsScene::toolOffsetProtractor);
     protractor->setData(UBGraphicsItemData::ItemLayerType, QVariant(UBItemLayerType::Tool));
 
     graphicsItemFromSvg(protractor);
@@ -2676,7 +2686,8 @@ UBGraphicsTriangle* UBSvgSubsetAdaptor::UBSvgSubsetReader::triangleFromSvg()
 {
     UBGraphicsTriangle* triangle = new UBGraphicsTriangle();
 
-    triangle->setZValue(UBGraphicsScene::toolLayerStart + UBGraphicsScene::toolOffsetTriangle);
+//    triangle->setZValue(UBGraphicsScene::toolLayerStart + UBGraphicsScene::toolOffsetTriangle);
+    UBGraphicsItem::assignZValue(triangle, UBGraphicsScene::toolLayerStart + UBGraphicsScene::toolOffsetTriangle);
     triangle->setData(UBGraphicsItemData::ItemLayerType, QVariant(UBItemLayerType::Tool));
 
     graphicsItemFromSvg(triangle);
@@ -2695,7 +2706,6 @@ UBGraphicsTriangle* UBSvgSubsetAdaptor::UBSvgSubsetReader::triangleFromSvg()
         triangle->setRect(svgX.toString().toFloat(), svgY.toString().toFloat(), svgWidth.toString().toFloat(), svgHeight.toString().toFloat(), orientation);
     }
 
-
     triangle->setVisible(true);
     return triangle;
 }
@@ -2703,7 +2713,8 @@ UBGraphicsTriangle* UBSvgSubsetAdaptor::UBSvgSubsetReader::triangleFromSvg()
 UBGraphicsCache* UBSvgSubsetAdaptor::UBSvgSubsetReader::cacheFromSvg()
 {
     UBGraphicsCache* pCache = new UBGraphicsCache();
-    //pCache->setZValue(UBGraphicsScene::toolLayerStart + UBGraphicsScene::toolOffsetCache);
+    pCache->setZValue(UBGraphicsScene::toolLayerStart + UBGraphicsScene::toolOffsetCache);
+//    UBGraphicsItem::assignZValue(pCache, UBGraphicsScene::toolLayerStart + UBGraphicsScene::toolOffsetCache);
     pCache->setData(UBGraphicsItemData::ItemLayerType, QVariant(UBItemLayerType::Tool));
 
     graphicsItemFromSvg(pCache);
diff --git a/src/board/UBBoardController.cpp b/src/board/UBBoardController.cpp
index 829c07ef..5c63fec8 100644
--- a/src/board/UBBoardController.cpp
+++ b/src/board/UBBoardController.cpp
@@ -1842,7 +1842,8 @@ void UBBoardController::processMimeData(const QMimeData* pMimeData, const QPoint
 
                 if (gi)
                 {
-                    gi->setZValue(mActiveScene->getNextObjectZIndex());
+//                    gi->setZValue(mActiveScene->getNextObjectZIndex());
+                    UBGraphicsItem::assignZValue(gi, mActiveScene->getNextObjectZIndex());
                     mActiveScene->addItem(gi);
                     gi->setPos(gi->pos() + QPointF(50, 50));
                 }
diff --git a/src/core/UB.h b/src/core/UB.h
index fbe7dd77..83a4b456 100644
--- a/src/core/UB.h
+++ b/src/core/UB.h
@@ -78,6 +78,7 @@ struct UBGraphicsItemData
         ItemLayerType
         , ItemLocked
         , ItemEditable//for text only
+        , ItemOwnZValue
     };
 };
 
diff --git a/src/domain/UBGraphicsAudioItem.cpp b/src/domain/UBGraphicsAudioItem.cpp
index 12a2eae6..d38e27b7 100644
--- a/src/domain/UBGraphicsAudioItem.cpp
+++ b/src/domain/UBGraphicsAudioItem.cpp
@@ -95,7 +95,8 @@ UBItem* UBGraphicsAudioItem::deepCopy() const
     UBGraphicsAudioItem *copy = new UBGraphicsAudioItem(audioUrl, parentItem());
 
     copy->setPos(this->pos());
-    copy->setZValue(this->zValue());
+//    copy->setZValue(this->zValue());
+    UBGraphicsItem::assignZValue(copy, this->zValue());
     copy->setTransform(this->transform());
     copy->setFlag(QGraphicsItem::ItemIsMovable, true);
     copy->setFlag(QGraphicsItem::ItemIsSelectable, true);
diff --git a/src/domain/UBGraphicsItemDelegate.cpp b/src/domain/UBGraphicsItemDelegate.cpp
index 7cc8fa96..de335a3a 100644
--- a/src/domain/UBGraphicsItemDelegate.cpp
+++ b/src/domain/UBGraphicsItemDelegate.cpp
@@ -72,7 +72,8 @@ void UBGraphicsItemDelegate::init()
 {
     mFrame = new UBGraphicsDelegateFrame(this, QRectF(0, 0, 0, 0), mFrameWidth, mRespectRatio);
     mFrame->hide();
-    mFrame->setZValue(UBGraphicsScene::toolLayerStart + 1);
+//    mFrame->setZValue(UBGraphicsScene::toolLayerStart + 1);
+    UBGraphicsItem::assignZValue(mFrame, UBGraphicsScene::toolLayerStart + 1);
     mFrame->setFlag(QGraphicsItem::ItemIsSelectable, true);
 
     mDeleteButton = new DelegateButton(":/images/close.svg", mDelegated, mFrame);
@@ -92,7 +93,8 @@ void UBGraphicsItemDelegate::init()
     foreach(DelegateButton* button, mButtons)
     {
         button->hide();
-        button->setZValue(UBGraphicsScene::toolLayerStart + 2);
+//        button->setZValue(UBGraphicsScene::toolLayerStart + 2);
+        UBGraphicsItem::assignZValue(button, UBGraphicsScene::toolLayerStart + 2);
         button->setFlag(QGraphicsItem::ItemIsSelectable, true);
     }
 }
diff --git a/src/domain/UBGraphicsItemTransformUndoCommand.cpp b/src/domain/UBGraphicsItemTransformUndoCommand.cpp
index 0d799f0a..e56027ea 100644
--- a/src/domain/UBGraphicsItemTransformUndoCommand.cpp
+++ b/src/domain/UBGraphicsItemTransformUndoCommand.cpp
@@ -15,6 +15,7 @@
 
 #include "UBGraphicsItemTransformUndoCommand.h"
 #include "UBResizableGraphicsItem.h"
+#include "domain/UBItem.h"
 
 #include "core/memcheck.h"
 
@@ -48,7 +49,8 @@ void UBGraphicsItemTransformUndoCommand::undo()
 {
     mItem->setPos(mPreviousPosition);
     mItem->setTransform(mPreviousTransform);
-    mItem->setZValue(mPreviousZValue);
+//    mItem->setZValue(mPreviousZValue);
+    UBGraphicsItem::assignZValue(mItem, mPreviousZValue);
 
     UBResizableGraphicsItem* resizableItem = dynamic_cast<UBResizableGraphicsItem*>(mItem);
 
@@ -60,7 +62,8 @@ void UBGraphicsItemTransformUndoCommand::redo()
 {
     mItem->setPos(mCurrentPosition);
     mItem->setTransform(mCurrentTransform);
-    mItem->setZValue(mCurrentZValue);
+//    mItem->setZValue(mCurrentZValue);
+    UBGraphicsItem::assignZValue(mItem, mCurrentZValue);
 
     UBResizableGraphicsItem* resizableItem = dynamic_cast<UBResizableGraphicsItem*>(mItem);
 
diff --git a/src/domain/UBGraphicsPDFItem.cpp b/src/domain/UBGraphicsPDFItem.cpp
index 7838358f..704ba676 100644
--- a/src/domain/UBGraphicsPDFItem.cpp
+++ b/src/domain/UBGraphicsPDFItem.cpp
@@ -84,7 +84,8 @@ UBItem* UBGraphicsPDFItem::deepCopy() const
     UBGraphicsPDFItem *copy =  new UBGraphicsPDFItem(mRenderer, mPageNumber, parentItem());
 
     copy->setPos(this->pos());
-    copy->setZValue(this->zValue());
+//    copy->setZValue(this->zValue());
+    UBGraphicsItem::assignZValue(copy, this->zValue());
     copy->setTransform(this->transform());
     copy->setFlag(QGraphicsItem::ItemIsMovable, true);
     copy->setFlag(QGraphicsItem::ItemIsSelectable, true);
@@ -134,7 +135,8 @@ UBGraphicsPixmapItem* UBGraphicsPDFItem::toPixmapItem() const
     pixmapItem->setPixmap(pixmap);
 
     pixmapItem->setPos(this->pos());
-    pixmapItem->setZValue(this->zValue());
+//    pixmapItem->setZValue(this->zValue());
+    UBGraphicsItem::assignZValue(pixmapItem, this->zValue());
     pixmapItem->setTransform(this->transform());
     pixmapItem->setFlag(QGraphicsItem::ItemIsMovable, true);
     pixmapItem->setFlag(QGraphicsItem::ItemIsSelectable, true);
diff --git a/src/domain/UBGraphicsPixmapItem.cpp b/src/domain/UBGraphicsPixmapItem.cpp
index edffb90d..ceb4fd28 100644
--- a/src/domain/UBGraphicsPixmapItem.cpp
+++ b/src/domain/UBGraphicsPixmapItem.cpp
@@ -98,7 +98,8 @@ UBItem* UBGraphicsPixmapItem::deepCopy() const
 
    copy->setPixmap(this->pixmap());
    copy->setPos(this->pos());
-   copy->setZValue(this->zValue());
+//   copy->setZValue(this->zValue());
+   UBGraphicsItem::assignZValue(copy, this->zValue());
    copy->setTransform(this->transform());
    copy->setFlag(QGraphicsItem::ItemIsMovable, true);
    copy->setFlag(QGraphicsItem::ItemIsSelectable, true);
diff --git a/src/domain/UBGraphicsPolygonItem.cpp b/src/domain/UBGraphicsPolygonItem.cpp
index c8153ca4..d2e96e25 100644
--- a/src/domain/UBGraphicsPolygonItem.cpp
+++ b/src/domain/UBGraphicsPolygonItem.cpp
@@ -153,7 +153,9 @@ UBGraphicsPolygonItem* UBGraphicsPolygonItem::deepCopy(const QPolygonF& pol) con
     copy->setPen(this->pen());
     copy->mHasAlpha = this->mHasAlpha;
 
-    copy->setZValue(this->zValue());
+//    copy->setZValue(this->zValue());
+    UBGraphicsItem::assignZValue(copy, this->zValue());
+
 
     copy->setColorOnDarkBackground(this->colorOnDarkBackground());
     copy->setColorOnLightBackground(this->colorOnLightBackground());
diff --git a/src/domain/UBGraphicsScene.cpp b/src/domain/UBGraphicsScene.cpp
index 476dd289..d4a7f8d8 100644
--- a/src/domain/UBGraphicsScene.cpp
+++ b/src/domain/UBGraphicsScene.cpp
@@ -75,6 +75,8 @@ qreal UBGraphicsScene::toolOffsetEraser = 200;
 qreal UBGraphicsScene::toolOffsetCurtain = 1000;
 qreal UBGraphicsScene::toolOffsetPointer = 1100;
 
+qreal UBGraphicsScene::toolOffsetCache = 1000;//Didier please define offset you want
+
 UBGraphicsScene::UBGraphicsScene(UBDocumentProxy* parent)
     : UBCoreGraphicsScene(parent)
     , mEraser(0)
@@ -824,8 +826,8 @@ void UBGraphicsScene::initPolygonItem(UBGraphicsPolygonItem* polygonItem)
 
     polygonItem->setData(UBGraphicsItemData::ItemLayerType, QVariant(UBItemLayerType::Graphic));
 
-    polygonItem->setZValue(getNextDrawingZIndex());
-
+//    polygonItem->setZValue(getNextDrawingZIndex());
+    UBGraphicsItem::assignZValue(polygonItem, getNextDrawingZIndex());
 }
 
 
@@ -1035,7 +1037,8 @@ UBGraphicsPixmapItem* UBGraphicsScene::addPixmap(const QPixmap& pPixmap, const Q
 
     pixmapItem->setFlag(QGraphicsItem::ItemIsMovable, true);
     pixmapItem->setFlag(QGraphicsItem::ItemIsSelectable, true);
-    pixmapItem->setZValue(getNextObjectZIndex());
+//    pixmapItem->setZValue(getNextObjectZIndex());
+    UBGraphicsItem::assignZValue(pixmapItem, getNextObjectZIndex());
 
     pixmapItem->setPixmap(pPixmap);
 
@@ -1083,7 +1086,8 @@ UBGraphicsVideoItem* UBGraphicsScene::addVideo(const QUrl& pVideoFileUrl, bool s
 
     videoItem->setFlag(QGraphicsItem::ItemIsMovable, true);
     videoItem->setFlag(QGraphicsItem::ItemIsSelectable, true);
-    videoItem->setZValue(getNextObjectZIndex());
+//    videoItem->setZValue(getNextObjectZIndex());
+    UBGraphicsItem::assignZValue(videoItem, getNextObjectZIndex());
 
     addItem(videoItem);
 
@@ -1113,7 +1117,8 @@ UBGraphicsAudioItem* UBGraphicsScene::addAudio(const QUrl& pAudioFileUrl, bool s
 
     audioItem->setFlag(QGraphicsItem::ItemIsMovable, true);
     audioItem->setFlag(QGraphicsItem::ItemIsSelectable, true);
-    audioItem->setZValue(getNextObjectZIndex());
+//    audioItem->setZValue(getNextObjectZIndex());
+    UBGraphicsItem::assignZValue(audioItem, getNextObjectZIndex());
 
     addItem(audioItem);
 
@@ -1178,7 +1183,8 @@ UBGraphicsW3CWidgetItem* UBGraphicsScene::addW3CWidget(const QUrl& pWidgetUrl, c
 void UBGraphicsScene::addGraphicsWidget(UBGraphicsWidgetItem* graphicsWidget, const QPointF& pPos)
 {
     graphicsWidget->setFlag(QGraphicsItem::ItemIsSelectable, true);
-    graphicsWidget->setZValue(getNextObjectZIndex());
+//    graphicsWidget->setZValue(getNextObjectZIndex());
+    UBGraphicsItem::assignZValue(graphicsWidget, getNextObjectZIndex());
 
     addItem(graphicsWidget);
 
@@ -1238,7 +1244,8 @@ UBGraphicsSvgItem* UBGraphicsScene::addSvg(const QUrl& pSvgFileUrl, const QPoint
 
     svgItem->setFlag(QGraphicsItem::ItemIsMovable, true);
     svgItem->setFlag(QGraphicsItem::ItemIsSelectable, true);
-    svgItem->setZValue(getNextObjectZIndex());
+//    svgItem->setZValue(getNextObjectZIndex());
+    UBGraphicsItem::assignZValue(svgItem, getNextObjectZIndex());
 
     qreal sscale = 1 / UBApplication::boardController->systemScaleFactor();
     svgItem->scale(sscale, sscale);
@@ -1271,7 +1278,8 @@ UBGraphicsTextItem* UBGraphicsScene::addTextWithFont(const QString& pString, con
 {
     UBGraphicsTextItem *textItem = new UBGraphicsTextItem();
     textItem->setPlainText(pString);
-    textItem->setZValue(getNextObjectZIndex());
+//    textItem->setZValue(getNextObjectZIndex());
+    UBGraphicsItem::assignZValue(textItem, getNextObjectZIndex());
 
     QFont font = textItem->font();
 
@@ -1326,7 +1334,8 @@ UBGraphicsTextItem *UBGraphicsScene::addTextHtml(const QString &pString, const Q
     UBGraphicsTextItem *textItem = new UBGraphicsTextItem();
     textItem->setPlainText("");
     textItem->setHtml(pString);
-    textItem->setZValue(getNextObjectZIndex());
+//    textItem->setZValue(getNextObjectZIndex());
+    UBGraphicsItem::assignZValue(textItem, getNextObjectZIndex());
 
     addItem(textItem);
     textItem->show();
@@ -1337,7 +1346,6 @@ UBGraphicsTextItem *UBGraphicsScene::addTextHtml(const QString &pString, const Q
     connect(textItem, SIGNAL(textUndoCommandAdded(UBGraphicsTextItem *)),
             this,     SLOT(textUndoCommandAdded(UBGraphicsTextItem *)));
 
-//    textItem->setSelected(true);
     textItem->setFocus();
 
     setDocumentUpdated();
@@ -1425,7 +1433,8 @@ QGraphicsItem* UBGraphicsScene::setAsBackgroundObject(QGraphicsItem* item, bool
         item->setAcceptedMouseButtons(Qt::NoButton);
         item->setData(UBGraphicsItemData::ItemLayerType, UBItemLayerType::FixedBackground);
 
-        item->setZValue(backgroundLayerStart);
+//        item->setZValue(backgroundLayerStart);
+        UBGraphicsItem::assignZValue(item, backgroundLayerStart);
 
         if (pAdaptTransformation)
         {
@@ -1529,7 +1538,9 @@ void UBGraphicsScene::addRuler(QPointF center)
     QRectF rect = ruler->rect();
     ruler->setRect(center.x() - rect.width()/2, center.y() - rect.height()/2, rect.width(), rect.height());
 
-    ruler->setZValue(toolLayerStart + toolOffsetRuler);
+//    ruler->setZValue(toolLayerStart + toolOffsetRuler);
+    UBGraphicsItem::assignZValue(ruler, toolLayerStart + toolOffsetRuler);
+
     ruler->setData(UBGraphicsItemData::ItemLayerType, QVariant(UBItemLayerType::Tool));
 
     addItem(ruler);
@@ -1546,7 +1557,9 @@ void UBGraphicsScene::addProtractor(QPointF center)
     UBGraphicsProtractor* protractor = new UBGraphicsProtractor(); // mem : owned and destroyed by the scene
     mTools << protractor;
 
-    protractor->setZValue(toolLayerStart + toolOffsetProtractor);
+//    protractor->setZValue(toolLayerStart + toolOffsetProtractor);
+    UBGraphicsItem::assignZValue(protractor, toolLayerStart + toolOffsetProtractor);
+
     protractor->setData(UBGraphicsItemData::ItemLayerType, QVariant(UBItemLayerType::Tool));
 
     addItem(protractor);
@@ -1565,7 +1578,9 @@ void UBGraphicsScene::addTriangle(QPointF center)
     UBGraphicsTriangle* triangle = new UBGraphicsTriangle(); // mem : owned and destroyed by the scene
     mTools << triangle;
 
-    triangle->setZValue(toolLayerStart + toolOffsetProtractor);
+//    triangle->setZValue(toolLayerStart + toolOffsetProtractor);
+    UBGraphicsItem::assignZValue(triangle, toolLayerStart + toolOffsetTriangle);
+
     triangle->setData(UBGraphicsItemData::ItemLayerType, QVariant(UBItemLayerType::Tool));
 
     addItem(triangle);
@@ -1700,7 +1715,9 @@ void UBGraphicsScene::addCompass(QPointF center)
     QRectF rect = compass->rect();
     compass->setRect(center.x() - rect.width() / 2, center.y() - rect.height() / 2, rect.width(), rect.height());
 
-    compass->setZValue(toolLayerStart + toolOffsetCompass);
+//    compass->setZValue(toolLayerStart + toolOffsetCompass);
+    UBGraphicsItem::assignZValue(compass, toolLayerStart + toolOffsetCompass);
+
     compass->setData(UBGraphicsItemData::ItemLayerType, QVariant(UBItemLayerType::Tool));
 
     compass->setVisible(true);
@@ -1740,7 +1757,10 @@ void UBGraphicsScene::addMask()
         view = (QGraphicsView*)UBApplication::boardController->controlView();
 
     QPolygonF polygon = view->mapToScene(view->rect());
-    curtain->setZValue(toolLayerStart + toolOffsetCurtain);
+
+//    curtain->setZValue(toolLayerStart + toolOffsetCurtain);
+    UBGraphicsItem::assignZValue(curtain, toolLayerStart + toolOffsetCurtain);
+
     QRectF rect = polygon.boundingRect();
     qreal xScale = view->matrix().m11();
     qreal yScale = view->matrix().m22();
diff --git a/src/domain/UBGraphicsSvgItem.cpp b/src/domain/UBGraphicsSvgItem.cpp
index cfd3509a..9d8798ec 100644
--- a/src/domain/UBGraphicsSvgItem.cpp
+++ b/src/domain/UBGraphicsSvgItem.cpp
@@ -132,7 +132,8 @@ UBItem* UBGraphicsSvgItem::deepCopy() const
     UBGraphicsSvgItem* copy = new UBGraphicsSvgItem(this->fileData());
 
     copy->setPos(this->pos());
-    copy->setZValue(this->zValue());
+//    copy->setZValue(this->zValue());
+    UBGraphicsItem::assignZValue(copy, this->zValue());
     copy->setTransform(this->transform());
     copy->setFlag(QGraphicsItem::ItemIsMovable, true);
     copy->setFlag(QGraphicsItem::ItemIsSelectable, true);
@@ -186,7 +187,8 @@ UBGraphicsPixmapItem* UBGraphicsSvgItem::toPixmapItem() const
     pixmapItem->setPixmap(QPixmap::fromImage(image));
 
     pixmapItem->setPos(this->pos());
-    pixmapItem->setZValue(this->zValue());
+//    pixmapItem->setZValue(this->zValue());
+    UBGraphicsItem::assignZValue(pixmapItem, this->zValue());
     pixmapItem->setTransform(this->transform());
     pixmapItem->setFlag(QGraphicsItem::ItemIsMovable, true);
     pixmapItem->setFlag(QGraphicsItem::ItemIsSelectable, true);
diff --git a/src/domain/UBGraphicsTextItem.cpp b/src/domain/UBGraphicsTextItem.cpp
index 8770a435..0d01527a 100644
--- a/src/domain/UBGraphicsTextItem.cpp
+++ b/src/domain/UBGraphicsTextItem.cpp
@@ -205,7 +205,8 @@ UBItem* UBGraphicsTextItem::deepCopy() const
 
     copy->setHtml(toHtml());
     copy->setPos(this->pos());
-    copy->setZValue(this->zValue());
+//    copy->setZValue(this->zValue());
+    UBGraphicsItem::assignZValue(copy, this->zValue());
     copy->setTransform(this->transform());
     copy->setFlag(QGraphicsItem::ItemIsMovable, true);
     copy->setFlag(QGraphicsItem::ItemIsSelectable, true);
diff --git a/src/domain/UBGraphicsVideoItem.cpp b/src/domain/UBGraphicsVideoItem.cpp
index 841667cf..c1e57e4d 100644
--- a/src/domain/UBGraphicsVideoItem.cpp
+++ b/src/domain/UBGraphicsVideoItem.cpp
@@ -68,7 +68,8 @@ UBItem* UBGraphicsVideoItem::deepCopy() const
     UBGraphicsVideoItem *copy = new UBGraphicsVideoItem(videoUrl, parentItem());
 
     copy->setPos(this->pos());
-    copy->setZValue(this->zValue());
+//    copy->setZValue(this->zValue());
+    UBGraphicsItem::assignZValue(copy, this->zValue());
     copy->setTransform(this->transform());
     copy->setFlag(QGraphicsItem::ItemIsMovable, true);
     copy->setFlag(QGraphicsItem::ItemIsSelectable, true);
diff --git a/src/domain/UBGraphicsVideoItemDelegate.cpp b/src/domain/UBGraphicsVideoItemDelegate.cpp
index 429194b0..99ba687b 100644
--- a/src/domain/UBGraphicsVideoItemDelegate.cpp
+++ b/src/domain/UBGraphicsVideoItemDelegate.cpp
@@ -52,7 +52,8 @@ void UBGraphicsVideoItemDelegate::buildButtons()
     mMuteButton->hide();
 
     mVideoControl = new DelegateVideoControl(delegated(), mFrame);
-    mVideoControl->setZValue(UBGraphicsScene::toolLayerStart + 2);
+//    mVideoControl->setZValue(UBGraphicsScene::toolLayerStart + 2);
+    UBGraphicsItem::assignZValue(mVideoControl, UBGraphicsScene::toolLayerStart + 2);
     mVideoControl->setFlag(QGraphicsItem::ItemIsSelectable, true);
 
     connect(mPlayPauseButton, SIGNAL(clicked(bool)), this, SLOT(togglePlayPause()));
diff --git a/src/domain/UBGraphicsWidgetItem.cpp b/src/domain/UBGraphicsWidgetItem.cpp
index b1246f2a..a786e55a 100644
--- a/src/domain/UBGraphicsWidgetItem.cpp
+++ b/src/domain/UBGraphicsWidgetItem.cpp
@@ -366,7 +366,8 @@ UBItem* UBGraphicsW3CWidgetItem::deepCopy() const
     UBGraphicsW3CWidgetItem *copy = new UBGraphicsW3CWidgetItem(mWebKitWidget->widgetUrl(), parentItem());
 
     copy->setPos(this->pos());
-    copy->setZValue(this->zValue());
+//    copy->setZValue(this->zValue());
+    UBGraphicsItem::assignZValue(copy, this->zValue());
     copy->setTransform(this->transform());
     copy->setFlag(QGraphicsItem::ItemIsMovable, true);
     copy->setFlag(QGraphicsItem::ItemIsSelectable, true);
diff --git a/src/domain/UBItem.cpp b/src/domain/UBItem.cpp
index 4a3e1643..3e6f68cf 100644
--- a/src/domain/UBItem.cpp
+++ b/src/domain/UBItem.cpp
@@ -28,3 +28,9 @@ UBItem::~UBItem()
 {
     // NOOP
 }
+
+void UBGraphicsItem::assignZValue(QGraphicsItem *item, int value)
+{
+    item->setZValue(value);
+    item->setData(UBGraphicsItemData::ItemOwnZValue, value);
+}
diff --git a/src/domain/UBItem.h b/src/domain/UBItem.h
index 328a3c37..7ae29988 100644
--- a/src/domain/UBItem.h
+++ b/src/domain/UBItem.h
@@ -100,6 +100,7 @@ protected:
 
 public:
 
+    static void assignZValue(QGraphicsItem*, int value);
     virtual UBGraphicsItemDelegate *Delegate() const  = 0;
 
     virtual void remove() = 0;
diff --git a/src/gui/UBLibraryWidget.cpp b/src/gui/UBLibraryWidget.cpp
index 22c27adc..963bd4e2 100644
--- a/src/gui/UBLibraryWidget.cpp
+++ b/src/gui/UBLibraryWidget.cpp
@@ -39,9 +39,9 @@
  */
 UBLibraryWidget::UBLibraryWidget(QWidget *parent, const char *name):UBThumbnailWidget(parent)
     , chainedElements(NULL)
+    , mLibraryController(NULL)
     , mpCrntDir(NULL)
     , mpCrntElem(NULL)
-    , mLibraryController(NULL)
     , mpTmpElem(NULL)
 {
     setObjectName(name);
diff --git a/src/gui/UBThumbnailWidget.h b/src/gui/UBThumbnailWidget.h
index c4fa103f..5f0543f8 100644
--- a/src/gui/UBThumbnailWidget.h
+++ b/src/gui/UBThumbnailWidget.h
@@ -23,6 +23,7 @@
 
 #include "frameworks/UBCoreGraphicsScene.h"
 #include "core/UBSettings.h"
+#include "domain/UBItem.h"
 
 #define STARTDRAGTIME   1000000
 #define BUTTONSIZE      48
@@ -147,7 +148,8 @@ class UBThumbnail
                     if (!mSelectionItem->scene())
                     {
                         item->scene()->addItem(mSelectionItem);
-                        mSelectionItem->setZValue(item->zValue() - 1);
+//                        mSelectionItem->setZValue(item->zValue() - 1);
+                        UBGraphicsItem::assignZValue(mSelectionItem, item->zValue() - 1);
                         mAddedToScene = true;
                     }
 
diff --git a/src/pdf-merger/Object.h b/src/pdf-merger/Object.h
index d2bc75ba..982d3734 100644
--- a/src/pdf-merger/Object.h
+++ b/src/pdf-merger/Object.h
@@ -48,7 +48,7 @@ namespace merge_lib
 		   std::string fileName = "", std::pair<unsigned int, unsigned int> streamBounds = std::make_pair ((unsigned int)0,(unsigned int)0), bool hasStream = false
 	   	       ):
 	   _number(objectNumber), _generationNumber(generationNumber), _oldNumber(objectNumber), _content(objectContent),_parents(),_children(),_isPassed(false),
-	   _fileName(fileName), _streamBounds(streamBounds), _hasStream(hasStream), _hasStreamInContent(false)
+           _streamBounds(streamBounds), _fileName(fileName), _hasStream(hasStream), _hasStreamInContent(false)
 	   {
 	   }
 	   virtual ~Object();
diff --git a/src/tools/UBGraphicsCache.cpp b/src/tools/UBGraphicsCache.cpp
index 231399c3..a7e97895 100644
--- a/src/tools/UBGraphicsCache.cpp
+++ b/src/tools/UBGraphicsCache.cpp
@@ -33,7 +33,8 @@ UBGraphicsCache::UBGraphicsCache():QGraphicsRectItem()
     // Get the board size and pass it to the shape
     QRect boardRect = UBApplication::boardController->displayView()->rect();
     setRect(-15*boardRect.width(), -15*boardRect.height(), 30*boardRect.width(), 30*boardRect.height());
-    setZValue(CACHE_ZVALUE);
+//    setZValue(CACHE_ZVALUE);
+    UBGraphicsItem::assignZValue(this, CACHE_ZVALUE);
     setData(Qt::UserRole, QVariant("Cache"));
 }
 
@@ -48,7 +49,8 @@ UBItem* UBGraphicsCache::deepCopy() const
 
     copy->setPos(this->pos());
     copy->setRect(this->rect());
-    copy->setZValue(this->zValue());
+//    copy->setZValue(this->zValue());
+    UBGraphicsItem::assignZValue(copy, this->zValue());
     copy->setTransform(this->transform());
 
     // TODO UB 4.7 ... complete all members ?
@@ -90,7 +92,8 @@ void UBGraphicsCache::paint(QPainter *painter, const QStyleOptionGraphicsItem *o
     //Q_UNUSED(option);
     Q_UNUSED(widget);
 
-    setZValue(CACHE_ZVALUE);
+//    setZValue(CACHE_ZVALUE);
+    UBGraphicsItem::assignZValue(this, CACHE_ZVALUE);
 
     painter->setBrush(mMaskColor);
     painter->setPen(mMaskColor);
diff --git a/src/tools/UBGraphicsCompass.cpp b/src/tools/UBGraphicsCompass.cpp
index d0374c11..6e13b125 100644
--- a/src/tools/UBGraphicsCompass.cpp
+++ b/src/tools/UBGraphicsCompass.cpp
@@ -85,7 +85,8 @@ UBItem* UBGraphicsCompass::deepCopy() const
 
     copy->setPos(this->pos());
     copy->setRect(this->rect());
-    copy->setZValue(this->zValue());
+//    copy->setZValue(this->zValue());
+    UBGraphicsItem::assignZValue(copy, this->zValue());
     copy->setTransform(this->transform());
 
    // TODO UB 4.7 ... complete all members ?
diff --git a/src/tools/UBGraphicsCurtainItem.cpp b/src/tools/UBGraphicsCurtainItem.cpp
index 118b92f2..3dfb21b6 100644
--- a/src/tools/UBGraphicsCurtainItem.cpp
+++ b/src/tools/UBGraphicsCurtainItem.cpp
@@ -57,8 +57,8 @@ UBGraphicsCurtainItem::~UBGraphicsCurtainItem()
 
 QVariant UBGraphicsCurtainItem::itemChange(GraphicsItemChange change, const QVariant &value)
 {
-    if (change == QGraphicsItem::ItemSelectedHasChanged && QGraphicsRectItem::scene() && isSelected())
-        setZValue(UBGraphicsScene::toolLayerStart + UBGraphicsScene::toolOffsetCurtain);
+//    if (change == QGraphicsItem::ItemSelectedHasChanged && QGraphicsRectItem::scene() && isSelected())
+//        setZValue(UBGraphicsScene::toolLayerStart + UBGraphicsScene::toolOffsetCurtain);
 
     QVariant newValue = value;
 
@@ -130,7 +130,8 @@ UBItem* UBGraphicsCurtainItem::deepCopy() const
    copy->setPos(this->pos());
    copy->setBrush(this->brush());
    copy->setPen(this->pen());
-   copy->setZValue(this->zValue());
+//   copy->setZValue(this->zValue());
+   UBGraphicsItem::assignZValue(copy, this->zValue());
    copy->setTransform(this->transform());
    copy->setFlag(QGraphicsItem::ItemIsMovable, true);
    copy->setFlag(QGraphicsItem::ItemIsSelectable, true);
diff --git a/src/tools/UBGraphicsCurtainItemDelegate.cpp b/src/tools/UBGraphicsCurtainItemDelegate.cpp
index 31eb0da7..a16685b6 100644
--- a/src/tools/UBGraphicsCurtainItemDelegate.cpp
+++ b/src/tools/UBGraphicsCurtainItemDelegate.cpp
@@ -52,7 +52,7 @@ bool UBGraphicsCurtainItemDelegate::mousePressEvent(QGraphicsSceneMouseEvent *ev
     if (!mDelegated->isSelected())
     {
         mDelegated->setSelected(true);
-        mDelegated->setZValue(UBGraphicsScene::toolLayerStart + UBGraphicsScene::toolOffsetCurtain);
+//        mDelegated->setZValue(UBGraphicsScene::toolLayerStart + UBGraphicsScene::toolOffsetCurtain);
         positionHandles();
 
         return true;
@@ -69,13 +69,13 @@ QVariant UBGraphicsCurtainItemDelegate::itemChange(QGraphicsItem::GraphicsItemCh
 {
     if (change == QGraphicsItem::ItemZValueHasChanged)
     {
-        mFrame->setZValue(mDelegated->zValue() + 1);
+//        mFrame->setZValue(mDelegated->zValue() + 1);
 
-        foreach(DelegateButton* button, mButtons)
-        {
-            button->setZValue(mDelegated->zValue() + 2);
-            button->setZValue(mDelegated->zValue() + 2);
-        }
+//        foreach(DelegateButton* button, mButtons)
+//        {
+//            button->setZValue(mDelegated->zValue() + 2);
+//            button->setZValue(mDelegated->zValue() + 2);
+//        }
     }
 
     if (change == QGraphicsItem::ItemVisibleHasChanged)
diff --git a/src/tools/UBGraphicsProtractor.cpp b/src/tools/UBGraphicsProtractor.cpp
index 43a84af1..bafb5689 100644
--- a/src/tools/UBGraphicsProtractor.cpp
+++ b/src/tools/UBGraphicsProtractor.cpp
@@ -580,7 +580,8 @@ UBItem* UBGraphicsProtractor::deepCopy() const
 
     copy->setPos(this->pos());
     copy->setRect(this->rect());
-    copy->setZValue(this->zValue());
+//    copy->setZValue(this->zValue());
+    UBGraphicsItem::assignZValue(copy, this->zValue());
     copy->setTransform(this->transform());
 
     copy->mCurrentAngle = this->mCurrentAngle;
diff --git a/src/tools/UBGraphicsRuler.cpp b/src/tools/UBGraphicsRuler.cpp
index cd15de78..2bf27719 100644
--- a/src/tools/UBGraphicsRuler.cpp
+++ b/src/tools/UBGraphicsRuler.cpp
@@ -74,7 +74,8 @@ UBItem* UBGraphicsRuler::deepCopy() const
 
     copy->setPos(this->pos());
     copy->setRect(this->rect());
-    copy->setZValue(this->zValue());
+//    copy->setZValue(this->zValue());
+    UBGraphicsItem::assignZValue(copy, this->zValue());
     copy->setTransform(this->transform());
 
     // TODO UB 4.7 ... complete all members ?
diff --git a/src/tools/UBGraphicsTriangle.cpp b/src/tools/UBGraphicsTriangle.cpp
index f6459f97..e5c7fdeb 100644
--- a/src/tools/UBGraphicsTriangle.cpp
+++ b/src/tools/UBGraphicsTriangle.cpp
@@ -93,7 +93,8 @@ UBItem* UBGraphicsTriangle::deepCopy(void) const
 
     copy->setPos(this->pos());
     copy->setPolygon(this->polygon());
-    copy->setZValue(this->zValue());
+//    copy->setZValue(this->zValue());
+    UBGraphicsItem::assignZValue(copy, this->zValue());
     copy->setTransform(this->transform());
 
     // TODO UB 4.7 ... complete all members ?