diff --git a/src/easyreflectometry/sample/collections/material_collection.py b/src/easyreflectometry/sample/collections/material_collection.py
index 875a5175..6295d8ef 100644
--- a/src/easyreflectometry/sample/collections/material_collection.py
+++ b/src/easyreflectometry/sample/collections/material_collection.py
@@ -3,9 +3,14 @@
 from typing import Tuple
 
 from ..elements.materials.material import Material
-from .base_element_collection import SIZE_DEFAULT_COLLECTION
 from .base_element_collection import BaseElementCollection
 
+DEFAULT_COLLECTION = (
+    Material(sld=0.0, isld=0.0, name='Air'),
+    Material(sld=6.335, isld=0.0, name='D2O'),
+    Material(sld=2.074, isld=0.0, name='Si'),
+)
+
 
 class MaterialCollection(BaseElementCollection):
     def __init__(
@@ -18,7 +23,7 @@ def __init__(
     ):
         if not materials:  # Empty tuple if no materials are provided
             if populate_if_none:
-                materials = (Material(interface=interface) for _ in range(SIZE_DEFAULT_COLLECTION))
+                materials = DEFAULT_COLLECTION  # (Material(interface=interface) for _ in range(SIZE_DEFAULT_COLLECTION))
             else:
                 materials = ()
         # Needed to ensure an empty list is created when saving and instatiating the object as_dict -> from_dict
@@ -37,6 +42,8 @@ def add_material(self, material: Optional[Material] = None):
 
         :param material: Material to add.
         """
+        if material is None:
+            material = Material(name='New EasyMaterial', interface=self.interface)
         self.append(material)
 
     def duplicate_material(self, index: int):
diff --git a/tests/sample/collections/test_material_collection.py b/tests/sample/collections/test_material_collection.py
index 5934a9d9..ca85e3ee 100644
--- a/tests/sample/collections/test_material_collection.py
+++ b/tests/sample/collections/test_material_collection.py
@@ -13,9 +13,10 @@ def test_default(self):
         p = MaterialCollection()
         assert p.name == 'EasyMaterials'
         assert p.interface is None
-        assert len(p) == 2
-        assert p[0].name == 'EasyMaterial'
-        assert p[1].name == 'EasyMaterial'
+        assert len(p) == 3
+        assert p[0].name == 'Air'
+        assert p[1].name == 'D2O'
+        assert p[2].name == 'Si'
 
     def test_from_pars(self):
         m = Material(6.908, -0.278, 'Boron')
@@ -37,8 +38,9 @@ def test_dict_repr(self):
         p = MaterialCollection()
         assert p._dict_repr == {
             'EasyMaterials': [
-                {'EasyMaterial': {'isld': '0.000e-6 1/Å^2', 'sld': '4.186e-6 1/Å^2'}},
-                {'EasyMaterial': {'isld': '0.000e-6 1/Å^2', 'sld': '4.186e-6 1/Å^2'}},
+                {'Air': {'isld': '0.000e-6 1/Å^2', 'sld': '0.000e-6 1/Å^2'}},
+                {'D2O': {'isld': '0.000e-6 1/Å^2', 'sld': '6.335e-6 1/Å^2'}},
+                {'Si': {'isld': '0.000e-6 1/Å^2', 'sld': '2.074e-6 1/Å^2'}},
             ]
         }
 
@@ -47,7 +49,7 @@ def test_repr(self):
         p.__repr__()
         assert (
             p.__repr__()
-            == 'EasyMaterials:\n- EasyMaterial:\n    sld: 4.186e-6 1/Å^2\n    isld: 0.000e-6 1/Å^2\n- EasyMaterial:\n    sld: 4.186e-6 1/Å^2\n    isld: 0.000e-6 1/Å^2\n'  # noqa: E501
+            == 'EasyMaterials:\n- Air:\n    sld: 0.000e-6 1/Å^2\n    isld: 0.000e-6 1/Å^2\n- D2O:\n    sld: 6.335e-6 1/Å^2\n    isld: 0.000e-6 1/Å^2\n- Si:\n    sld: 2.074e-6 1/Å^2\n    isld: 0.000e-6 1/Å^2\n'  # noqa: E501
         )
 
     def test_dict_round_trip(self):
@@ -56,7 +58,7 @@ def test_dict_round_trip(self):
         k = Material(0.487, 0.000, 'Potassium')
         p = MaterialCollection()
         p.insert(0, m)
-        p.append(k)
+        p.add_material(k)
         p_dict = p.as_dict()
         global_object.map._clear()
 
@@ -75,7 +77,7 @@ def test_add_material(self):
         p.add_material(m)
 
         # Then
-        assert p[2] == m
+        assert p[3] == m
 
     def test_duplicate_material(self):
         # Given
@@ -84,10 +86,10 @@ def test_duplicate_material(self):
         p.add_material(m)
 
         # When
-        p.duplicate_material(2)
+        p.duplicate_material(3)
 
         # Then
-        assert p[3].name == 'Boron duplicate'
+        assert p[4].name == 'Boron duplicate'
 
     def test_move_material_up(self):
         # Given
@@ -96,11 +98,11 @@ def test_move_material_up(self):
         p.add_material(k)
 
         # When
-        p.move_material_up(2)
+        p.move_material_up(3)
 
         # Then
-        assert p[1].name == 'Bottom'
-        assert p[2].name == 'EasyMaterial'
+        assert p[2].name == 'Bottom'
+        assert p[3].name == 'Si'
 
     def test_move_material_up_to_top_and_further(self):
         # Given
@@ -109,13 +111,14 @@ def test_move_material_up_to_top_and_further(self):
         p.add_material(m)
 
         # When
+        p.move_material_up(3)
         p.move_material_up(2)
         p.move_material_up(1)
         p.move_material_up(0)
 
         # Then
         assert p[0].name == 'Bottom'
-        assert p[2].name == 'EasyMaterial'
+        assert p[3].name == 'Si'
 
     def test_move_material_down(self):
         # Given
@@ -124,11 +127,11 @@ def test_move_material_down(self):
         p.add_material(m)
 
         # When
-        p.move_material_down(1)
+        p.move_material_down(2)
 
         # Then
-        assert p[1].name == 'Bottom'
-        assert p[2].name == 'EasyMaterial'
+        assert p[2].name == 'Bottom'
+        assert p[3].name == 'Si'
 
     def test_move_material_down_to_bottom_and_further(self):
         # Given
@@ -139,13 +142,13 @@ def test_move_material_down_to_bottom_and_further(self):
         p.add_material(m)
 
         # When
-        p.move_material_down(2)
         p.move_material_down(3)
+        p.move_material_down(4)
 
         # Then
-        assert p[0].name == 'EasyMaterial'
-        assert p[2].name == 'Bottom'
-        assert p[3].name == 'Middle'
+        assert p[0].name == 'Air'
+        assert p[3].name == 'Bottom'
+        assert p[4].name == 'Middle'
 
     def test_remove_material(self):
         # Given
@@ -157,6 +160,6 @@ def test_remove_material(self):
         p.remove_material(1)
 
         # Then
-        assert len(p) == 2
-        assert p[0].name == 'EasyMaterial'
-        assert p[1].name == 'Bottom'
+        assert len(p) == 3
+        assert p[0].name == 'Air'
+        assert p[2].name == 'Bottom'