diff --git a/screening/source/java/ch/systemsx/cisd/openbis/plugin/screening/client/web/client/application/detailviewers/PlateLayouter.java b/screening/source/java/ch/systemsx/cisd/openbis/plugin/screening/client/web/client/application/detailviewers/PlateLayouter.java
index c3b8fff18ab9d282620c5445920c44b519b8f47e..8d5f261ab387ee88e9f8a84c720035c8501dbffa 100644
--- a/screening/source/java/ch/systemsx/cisd/openbis/plugin/screening/client/web/client/application/detailviewers/PlateLayouter.java
+++ b/screening/source/java/ch/systemsx/cisd/openbis/plugin/screening/client/web/client/application/detailviewers/PlateLayouter.java
@@ -317,7 +317,7 @@ public class PlateLayouter
         for (IEntityProperty property : properties)
         {
             PropertyType propertyType = property.getPropertyType();
-            tooltip += "<br>" + propertyType.getLabel() + ": " + property.tryGetAsString();
+            tooltip += "<br>" + propertyType.getLabel() + ": " + getPropertyDisplayText(property);
             Material material = property.getMaterial();
             if (material != null
                     && material.getMaterialType().getCode()
@@ -338,6 +338,18 @@ public class PlateLayouter
 
     }
 
+    private static String getPropertyDisplayText(IEntityProperty property)
+    {
+        Material material = property.getMaterial();
+        if (material != null)
+        {
+            return material.getCode();
+        } else
+        {
+            return property.tryGetAsString();
+        }
+    }
+
     private static String getWellDescription(WellMetadata metadata)
     {
         return "Well: " + metadata.getWellSample().getSubCode();