diff --git a/doc/materials/groups/MATGROUP_INVIS b/doc/materials/groups/MATGROUP_INVIS
new file mode 100644
index 0000000..741baef
--- /dev/null
+++ b/doc/materials/groups/MATGROUP_INVIS
@@ -0,0 +1,5 @@
+Gruppenid:
+MATGROUP_INVIS
+
+Name:
+unsichtbare Materialien