diff --git a/Mapping.cpp b/Mapping.cpp
index 1701421..1198c24 100644
--- a/Mapping.cpp
+++ b/Mapping.cpp
@@ -19,6 +19,7 @@
  */
 
 #include "Mapping.h"
+#include "MainWindow.h"
 
 UidAllocator Mapping::allocator;
 
@@ -35,3 +36,90 @@ Mapping::~Mapping() {
   allocator.free(getId());
 }
 
+void Mapping::read(const QDomElement& obj)
+{
+  // Read basic data.
+  Element::read(obj);
+
+  // Read paint.
+  int paintId = obj.attribute("paintId").toInt();
+  setPaint(MainWindow::instance()->getMappingManager().getPaintById(paintId));
+
+  // Read output shape.
+  _readShape(obj, true);
+
+  // Read input shape.
+  if (hasInputShape())
+  {
+    _readShape(obj, false);
+  }
+
+}
+
+void Mapping::write(QDomElement& obj)
+{
+  // Write basic data.
+  Element::write(obj);
+
+  // Write paint ID.
+  obj.setAttribute("paintId", getPaint()->getId());
+
+  // Write output shape.
+  _writeShape(obj, true);
+
+  // Write input shape.
+  if (hasInputShape())
+  {
+    _writeShape(obj, false);
+  }
+}
+
+void Mapping::_readShape(const QDomElement& obj, bool isOutput)
+{
+  QString tag       = isOutput ? "output" : "input";
+
+  QDomElement shapeObj = obj.firstChildElement(tag);
+
+  QString className = shapeObj.attribute("className");
+
+  qDebug() << "Found shape with classname: " << className << endl;
+
+  const QMetaObject* metaObject = MetaObjectRegistry::instance().getMetaObject(className);
+  if (metaObject)
+  {
+    // Create new instance.
+    MShape::ptr shape (qobject_cast<MShape*>(metaObject->newInstance()));
+    if (shape.isNull())
+    {
+      qDebug() << QObject::tr("Problem at creation of shape.") << endl;
+//      _xml.raiseError(QObject::tr("Problem at creation of paint."));
+    }
+    else
+      qDebug() << "Created new shape" << endl;
+
+    // Read shape.
+    shape->read(shapeObj);
+
+    // Set shape.
+    if (isOutput)
+      setShape(shape);
+    else
+      qDebug() << "Shit!!!!" << endl;
+
+  }
+
+  else
+  {
+    qDebug() << QObject::tr("Unable to create paint of type '%1'.").arg(className) << endl;
+  }
+
+}
+
+void Mapping::_writeShape(QDomElement& obj, bool isOutput)
+{
+  QString tag       = isOutput ? "output" : "input";
+  MShape::ptr shape = isOutput ? getShape() : getInputShape();
+  QDomElement shapeObj = obj.ownerDocument().createElement(tag);
+  shape->write(shapeObj);
+  obj.appendChild(shapeObj);
+}
diff --git a/Mapping.h b/Mapping.h
index 85f6b8c..499b02d 100644
--- a/Mapping.h
+++ b/Mapping.h
@@ -30,6 +30,11 @@
 
 #include "UidAllocator.h"
 
+#include "MetaObjectRegistry.h"
+
+// TODO: replace by ProjectAttribute
+//#include "ProjectWriter.h"
+
 /**
  * Mapping is the central concept of this software.
  *
@@ -119,6 +124,17 @@ public:
   float getComputedOpacity() const { return getOpacity() * _paint->getOpacity(); }
 
   void setPaint(Paint::ptr p) { _paint = p; }
+  void setShape(MShape::ptr s) { _shape = s; }
+
+  virtual void read(const QDomElement& obj);
+  virtual void write(QDomElement& obj);
+
+protected:
+  virtual QList<QString> _propertiesAttributes() const
+  { return Element::_propertiesAttributes() << "solo" << "visible" << "depth"; }
+
+  void _readShape(const QDomElement& obj, bool isOutput);
+  void _writeShape(QDomElement& obj, bool isOutput);
 };
 
 /**
@@ -128,14 +144,13 @@ class ColorMapping : public Mapping
 {
   Q_OBJECT
 public:
-  ColorMapping(Paint::ptr paint, MShape::ptr shape,
+  Q_INVOKABLE ColorMapping(Paint::ptr paint, MShape::ptr shape,
                uid id=NULL_UID)
     : Mapping(paint, shape, id) {}
 
   virtual QString getType() const {
     return getShape()->getType() + "_color";
   }
-
 };
 
 /**
@@ -149,6 +164,14 @@ private:
   MShape::ptr _inputShape;
 
 public:
+  Q_INVOKABLE TextureMapping(
+                 Paint::ptr paint,
+                 MShape::ptr shape, uid id=NULL_UID)
+    : Mapping(paint, shape, id),
+      _inputShape()
+  {
+
+  }
   TextureMapping(Paint::ptr paint,
                  MShape::ptr shape,
                  MShape::ptr inputShape, uid id=NULL_UID)
@@ -171,6 +194,7 @@ public:
 public:
   virtual bool hasInputShape() const { return true; }
   virtual MShape::ptr getInputShape() const { return _inputShape; }
+
 };
 
 #endif /* MAPPING_H_ */
diff --git a/Mesh.h b/Mesh.h
index 742275f..17b11ca 100644
--- a/Mesh.h
+++ b/Mesh.h
@@ -27,13 +27,13 @@ class Mesh : public Quad
 {
   Q_OBJECT
 
-  Q_PROPERTY(int nColumns READ nColumns)
-  Q_PROPERTY(int nRows    READ nRows)
+  Q_PROPERTY(int nColumns READ nColumns WRITE setNColumns)
+  Q_PROPERTY(int nRows    READ nRows    WRITE setNRows)
 
   typedef QVector<QVector<int> > IndexVector2d;
 
 public:
-  Mesh();
+  Q_INVOKABLE Mesh();
 
   // This constructor creates a quad mesh (four corners) using the same order as for the quad
   // constructor (ie. clockwise).
@@ -87,6 +87,13 @@ public:
   int nColumns() const { return _nColumns; }
   int nRows() const  { return _nRows; }
 
+  void setNColumns(int nColumns_) {
+    resize(nColumns_, nRows());
+  }
+  void setNRows(int nRows_) {
+    resize(nColumns(), nRows_);
+  }
+
   int nHorizontalQuads() const { return _nColumns-1; }
   int nVerticalQuads() const { return _nRows-1; }
 
diff --git a/ProjectWriter.cpp b/ProjectWriter.cpp
index 657c28c..398cdfe 100644
--- a/ProjectWriter.cpp
+++ b/ProjectWriter.cpp
@@ -39,8 +39,8 @@ bool ProjectWriter::writeFile(QIODevice *device)
   QDomElement project = doc.createElement("project");
   project.setAttribute("version", MM::VERSION);
 
+  // Paints.
   QDomElement paints = doc.createElement("paints");
-
   for (int i=0; i<manager.nPaints(); i++)
   {
     QDomElement paint = doc.createElement("paint");
@@ -48,7 +48,17 @@ bool ProjectWriter::writeFile(QIODevice *device)
     paints.appendChild(paint);
   }
 
+  // Mappings.
+  QDomElement mappings = doc.createElement("mappings");
+  for (int i=0; i<manager.nMappings(); i++)
+  {
+    QDomElement mapping = doc.createElement("mapping");
+    manager.getMapping(i)->write(mapping);
+    mappings.appendChild(mapping);
+  }
+
   project.appendChild(paints);
+  project.appendChild(mappings);
   doc.appendChild(project);
 
   QTextStream out(device);
diff --git a/ProjectWriter.h b/ProjectWriter.h
index 028d29b..da6c973 100644
--- a/ProjectWriter.h
+++ b/ProjectWriter.h
@@ -47,7 +47,7 @@ public:
     bool writeFile (QIODevice *device);
 
   private:
-    void writeProject();
+//    void writeProject();
 //    void writePaint(Paint::ptr paint);
 //    void writeItem (Paint *item);
 //    void writeItem (Mapping *item);
diff --git a/Quad.h b/Quad.h
index 89c0a40..eec1753 100644
--- a/Quad.h
+++ b/Quad.h
@@ -32,7 +32,7 @@ class Quad : public Polygon
 public:
   typedef QSharedPointer<Quad> ptr;
 
-  Quad() {}
+  Q_INVOKABLE Quad() {}
   Quad(QPointF p1, QPointF p2, QPointF p3, QPointF p4)
   {
     _addVertex(p1);
diff --git a/Shape.cpp b/Shape.cpp
index 1e0ab57..0f6841e 100644
--- a/Shape.cpp
+++ b/Shape.cpp
@@ -38,3 +38,27 @@ void MShape::translate(const QPointF& offset)
     *it += offset;
 }
 
+void MShape::read(const QDomElement& obj)
+{
+  // Read basic data.
+  Serializable::read(obj);
+}
+
+void MShape::write(QDomElement& obj)
+{
+  // Write basic data.
+  Serializable::write(obj);
+
+  // Write vertices.
+  QDomElement verticesObj = obj.ownerDocument().createElement("vertices");
+  for (int i=0; i<nVertices(); i++)
+  {
+    QDomElement vertexObj = obj.ownerDocument().createElement("vertex");
+    vertexObj.setAttribute("x", getVertex(i).x());
+    vertexObj.setAttribute("y", getVertex(i).y());
+    verticesObj.appendChild(vertexObj);
+  }
+
+  obj.appendChild(verticesObj);
+}
+
diff --git a/Shape.h b/Shape.h
index 33b0a16..dd8c29e 100644
--- a/Shape.h
+++ b/Shape.h
@@ -39,15 +39,16 @@
 #include <QSharedPointer>
 
 #include "Maths.h"
+#include "Serializable.h"
 
 /**
  * Shape represented by a series of control points.
  */
-class MShape : public QObject
+class MShape : public Serializable
 {
   Q_OBJECT
 
-  Q_PROPERTY(QVector<QPointF> vertices READ getVertices WRITE setVertices)
+  Q_PROPERTY(QVector<QPointF> vertices READ getVertices WRITE setVertices STORED false)
 public:
   typedef QSharedPointer<MShape> ptr;
 
@@ -101,6 +102,9 @@ public:
     vertices = vertices_;
   }
 
+  virtual void read(const QDomElement& obj);
+  virtual void write(QDomElement& obj);
+
 protected:
   QVector<QPointF> vertices;
 
diff --git a/Triangle.h b/Triangle.h
index 2dc6aab..38d3d4e 100644
--- a/Triangle.h
+++ b/Triangle.h
@@ -30,7 +30,7 @@ class Triangle : public Polygon
 {
   Q_OBJECT
 public:
-  Triangle() {}
+  Q_INVOKABLE Triangle() {}
   Triangle(QPointF p1, QPointF p2, QPointF p3)
   {
     _addVertex(p1);