diff --git a/dune/microstructure/prestrainedMaterial.hh b/dune/microstructure/prestrainedMaterial.hh
index 3634e4feeb60bb6ef9736ee68a5f6190b3da056e..e04cffb0e6328432c2461b196fcca0b53cf51b0f 100644
--- a/dune/microstructure/prestrainedMaterial.hh
+++ b/dune/microstructure/prestrainedMaterial.hh
@@ -8,6 +8,7 @@
 #include <dune/common/parametertree.hh>
 #include <dune/fufem/dunepython.hh>
 #include <dune/microstructure/matrix_operations.hh>
+#include <dune/microstructure/voigthelper.hh>
 
 // #include <dune/microstructure/materialDefinitions.hh> //deprecated
 
@@ -109,7 +110,7 @@ protected:
   // MatrixFunc L2_;
   // MatrixFunc L3_;
 
-  // Elasticity tensors (in voigt notation)
+  // Elasticity tensors (in Voigt notation)
   Dune::FieldMatrix<double,6,6> L1_;
   Dune::FieldMatrix<double,6,6> L2_;
   Dune::FieldMatrix<double,6,6> L3_;
@@ -590,20 +591,6 @@ Dune::FieldMatrix<double,6,6> setupPhase(const std::string phaseType, Python::Mo
   //-------------------------------------------------------------------------------
 
 
-  // --- Helpers
-  static Dune::FieldVector<double,6> MatrixToVoigt(const MatrixRT& G)
-  {
-    // return {G[0][0], G[1][1], G[2][2], G[1][2], G[0][2], G[0][1]};
-    return {G[0][0], G[1][1], G[2][2], 2.0*G[1][2], 2.0*G[0][2], 2.0*G[0][1]};
-
-  }
-
-  static MatrixRT VoigtToMatrix(const Dune::FieldVector<double,6>& v)
-  {
-    // return {{v[0], v[5], v[4]}, {v[5], v[1], v[3]}, {v[4], v[3], v[2]}};
-    return {{v[0], v[5]/2.0, v[4]/2.0}, {v[5]/2.0, v[1], v[3]/2.0}, {v[4]/2.0, v[3]/2.0, v[2]}};
-  }
-
   static Dune::FieldVector<double,6> strainToVoigt(const MatrixRT& G)
   {
     // return {G[0][0], G[1][1], G[2][2], G[1][2], G[0][2], G[0][1]};
@@ -630,14 +617,12 @@ Dune::FieldMatrix<double,6,6> setupPhase(const std::string phaseType, Python::Mo
     return {{v[0], v[5]/2.0, v[4]/2.0}, {v[5]/2.0, v[1], v[3]/2.0}, {v[4]/2.0, v[3]/2.0, v[2]}};
   }
 
-
-
-  MatrixRT applyElasticityTensor(const MatrixRT& G, const int& phase)  const  
+  MatrixRT applyElasticityTensor(const MatrixRT& G, const int& phase)  const
   {
     // FieldVector<double,6> G_tmp = {G[0][0], G[1][1], G[2][2], sqrt(2.0)*G[1][2], sqrt(2.0)*G[0][2], sqrt(2.0)*G[0][1]};
     // FieldVector<double,6> G_tmp = {G[0][0], G[1][1], G[2][2], G[1][2], G[0][2], G[0][1]};
-    Dune::FieldVector<double,6> G_tmp = MatrixToVoigt(G);
-    Dune::FieldVector<double,6> out(0);
+    VoigtVector<double,3> G_tmp = matrixToVoigt(G);
+    VoigtVector<double,3> out(0);
     // printvector(std::cout, G_tmp, "G_tmp", "--");
 
     // if (phase == 1)
@@ -689,7 +674,7 @@ Dune::FieldMatrix<double,6,6> setupPhase(const std::string phaseType, Python::Mo
 
 
     // printvector(std::cout, out, "out", "--");
-    return VoigtToMatrix(out);          // Muss hier stress zurücktransformieren! 
+    return voigtToMatrix(out);          // Muss hier stress zurücktransformieren!
     // return VoigtToStress(out);
     // return image as Matrix again
     // return {{out[0], (1.0/sqrt(2.0))*out[5], (1.0/sqrt(2.0))*out[4]}, {(1.0/sqrt(2.0))*out[5], out[1], (1.0/sqrt(2.0))*out[3]}, {(1.0/sqrt(2.0))*out[4], (1.0/sqrt(2.0))*out[3], out[2]}};
diff --git a/dune/microstructure/voigthelper.hh b/dune/microstructure/voigthelper.hh
new file mode 100644
index 0000000000000000000000000000000000000000..fbea65a183f9af269547f4da26dd9ae6376d6bab
--- /dev/null
+++ b/dune/microstructure/voigthelper.hh
@@ -0,0 +1,31 @@
+#ifndef DUNE_MICROSTRUCTURE_VOIGTHELPER_HH
+#define DUNE_MICROSTRUCTURE_VOIGTHELPER_HH
+
+/** \file
+ * \brief Various helper functions related to Voigt notation
+ */
+
+#include <dune/common/fvector.hh>
+#include <dune/common/fmatrix.hh>
+
+
+template<typename T, int dim>
+using VoigtVector = Dune::FieldVector<T,dim*(dim+1)/2>;
+
+template<typename T, int dim>
+using VoigtMatrix = Dune::FieldMatrix<T,dim*(dim+1)/2,dim*(dim+1)/2>;
+
+
+template<typename T>
+static VoigtVector<T,3> matrixToVoigt(const Dune::FieldMatrix<T,3,3>& matrix)
+{
+  return {matrix[0][0], matrix[1][1], matrix[2][2], 2.0*matrix[1][2], 2.0*matrix[0][2], 2.0*matrix[0][1]};
+}
+
+template<typename T>
+static Dune::FieldMatrix<T,3,3> voigtToMatrix(const VoigtVector<T,3>& v)
+{
+  return {{v[0], v[5]/2.0, v[4]/2.0}, {v[5]/2.0, v[1], v[3]/2.0}, {v[4]/2.0, v[3]/2.0, v[2]}};
+}
+
+#endif   // DUNE_MICROSTRUCTURE_VOIGTHELPER_HH