diff --git a/src/core/qgsabstractgeopdfexporter.cpp b/src/core/qgsabstractgeopdfexporter.cpp
index e76bb6d9cc1..fbbf29d5436 100644
--- a/src/core/qgsabstractgeopdfexporter.cpp
+++ b/src/core/qgsabstractgeopdfexporter.cpp
@@ -136,6 +136,29 @@ QString QgsAbstractGeoPdfExporter::generateTemporaryFilepath( const QString &fil
   return mTemporaryDir.filePath( filename );
 }
 
+bool QgsAbstractGeoPdfExporter::compositionModeSupported( QPainter::CompositionMode mode )
+{
+  switch ( mode )
+  {
+    case QPainter::CompositionMode_SourceOver:
+    case QPainter::CompositionMode_Multiply:
+    case QPainter::CompositionMode_Screen:
+    case QPainter::CompositionMode_Overlay:
+    case QPainter::CompositionMode_Darken:
+    case QPainter::CompositionMode_Lighten:
+    case QPainter::CompositionMode_ColorDodge:
+    case QPainter::CompositionMode_ColorBurn:
+    case QPainter::CompositionMode_HardLight:
+    case QPainter::CompositionMode_SoftLight:
+    case QPainter::CompositionMode_Difference:
+    case  QPainter::CompositionMode_Exclusion:
+      return true;
+
+    default:
+      return false;
+  }
+  return false;
+}
 
 void QgsAbstractGeoPdfExporter::pushRenderedFeature( const QString &layerId, const QgsAbstractGeoPdfExporter::RenderedFeature &feature, const QString &group )
 {
@@ -479,52 +502,7 @@ QString QgsAbstractGeoPdfExporter::createCompositionXml( const QList<ComponentLa
     {
       QDomElement blendingElement = doc.createElement( QStringLiteral( "Blending" ) );
       blendingElement.setAttribute( QStringLiteral( "opacity" ), component.opacity );
-      QString function;
-      switch ( component.compositionMode )
-      {
-        case QPainter::CompositionMode_SourceOver:
-          function = QStringLiteral( "Normal" );
-          break;
-        case QPainter::CompositionMode_Multiply:
-          function = QStringLiteral( "Multiply" );
-          break;
-        case QPainter::CompositionMode_Screen:
-          function = QStringLiteral( "Screen" );
-          break;
-        case QPainter::CompositionMode_Overlay:
-          function = QStringLiteral( "Overlay" );
-          break;
-        case QPainter::CompositionMode_Darken:
-          function = QStringLiteral( "Darken" );
-          break;
-        case QPainter::CompositionMode_Lighten:
-          function = QStringLiteral( "Lighten" );
-          break;
-        case QPainter::CompositionMode_ColorDodge:
-          function = QStringLiteral( "ColorDodge" );
-          break;
-        case QPainter::CompositionMode_ColorBurn:
-          function = QStringLiteral( "ColorBurn" );
-          break;
-        case QPainter::CompositionMode_HardLight:
-          function = QStringLiteral( "HardLight" );
-          break;
-        case QPainter::CompositionMode_SoftLight:
-          function = QStringLiteral( "SoftLight" );
-          break;
-        case QPainter::CompositionMode_Difference:
-          function = QStringLiteral( "Difference" );
-          break;
-        case  QPainter::CompositionMode_Exclusion:
-          function = QStringLiteral( "Exclusion" );
-          break;
-
-        default:
-          QgsDebugMsg( QStringLiteral( "Unsupported PDF blend mode %1" ).arg( component.compositionMode ) );
-          function = QStringLiteral( "Normal" );
-          break;
-      }
-      blendingElement.setAttribute( QStringLiteral( "function" ), function );
+      blendingElement.setAttribute( QStringLiteral( "function" ), compositionModeToString( component.compositionMode ) );
 
       pdfDataset.appendChild( blendingElement );
     }
@@ -608,3 +586,51 @@ QString QgsAbstractGeoPdfExporter::createCompositionXml( const QList<ComponentLa
   return composition;
 }
 
+QString QgsAbstractGeoPdfExporter::compositionModeToString( QPainter::CompositionMode mode )
+{
+  switch ( mode )
+  {
+    case QPainter::CompositionMode_SourceOver:
+      return QStringLiteral( "Normal" );
+
+    case QPainter::CompositionMode_Multiply:
+      return QStringLiteral( "Multiply" );
+
+    case QPainter::CompositionMode_Screen:
+      return QStringLiteral( "Screen" );
+
+    case QPainter::CompositionMode_Overlay:
+      return QStringLiteral( "Overlay" );
+
+    case QPainter::CompositionMode_Darken:
+      return QStringLiteral( "Darken" );
+
+    case QPainter::CompositionMode_Lighten:
+      return QStringLiteral( "Lighten" );
+
+    case QPainter::CompositionMode_ColorDodge:
+      return QStringLiteral( "ColorDodge" );
+
+    case QPainter::CompositionMode_ColorBurn:
+      return QStringLiteral( "ColorBurn" );
+
+    case QPainter::CompositionMode_HardLight:
+      return QStringLiteral( "HardLight" );
+
+    case QPainter::CompositionMode_SoftLight:
+      return QStringLiteral( "SoftLight" );
+
+    case QPainter::CompositionMode_Difference:
+      return QStringLiteral( "Difference" );
+
+    case  QPainter::CompositionMode_Exclusion:
+      return QStringLiteral( "Exclusion" );
+
+    default:
+      QgsDebugMsg( QStringLiteral( "Unsupported PDF blend mode %1" ).arg( mode ) );
+      return QStringLiteral( "Normal" );
+
+  }
+  return QString();
+}
+
diff --git a/src/core/qgsabstractgeopdfexporter.h b/src/core/qgsabstractgeopdfexporter.h
index af91e8a7cc5..6097693cece 100644
--- a/src/core/qgsabstractgeopdfexporter.h
+++ b/src/core/qgsabstractgeopdfexporter.h
@@ -311,6 +311,14 @@ class CORE_EXPORT QgsAbstractGeoPdfExporter
      */
     QString generateTemporaryFilepath( const QString &filename ) const;
 
+    /**
+     * Returns TRUE if the specified composition \a mode is supported for layers
+     * during GeoPDF exports.
+     *
+     * \since QGIS 3.14
+     */
+    static bool compositionModeSupported( QPainter::CompositionMode mode );
+
   protected:
 
     /**
@@ -358,6 +366,11 @@ class CORE_EXPORT QgsAbstractGeoPdfExporter
 
     QString createCompositionXml( const QList< QgsAbstractGeoPdfExporter::ComponentLayerDetail > &components, const ExportDetails &details );
 
+    /**
+     * Returns the GDAL string representation of the specified QPainter composition \a mode.
+     */
+    static QString compositionModeToString( QPainter::CompositionMode mode );
+
     friend class TestQgsLayoutGeoPdfExport;
     friend class TestQgsGeoPdfExport;
 };
diff --git a/tests/src/core/testqgsgeopdfexport.cpp b/tests/src/core/testqgsgeopdfexport.cpp
index bb1110c4c2d..ee1776b1698 100644
--- a/tests/src/core/testqgsgeopdfexport.cpp
+++ b/tests/src/core/testqgsgeopdfexport.cpp
@@ -61,6 +61,7 @@ class TestQgsGeoPdfExport : public QObject
     void testGeorefPolygon();
     void testGroups();
     void testCustomGroups();
+    void compositionMode();
 
   private:
 
@@ -587,5 +588,36 @@ void TestQgsGeoPdfExport::testCustomGroups()
 
 }
 
+void TestQgsGeoPdfExport::compositionMode()
+{
+  QVERIFY( QgsAbstractGeoPdfExporter::compositionModeSupported( QPainter::CompositionMode_SourceOver ) );
+  QVERIFY( QgsAbstractGeoPdfExporter::compositionModeSupported( QPainter::CompositionMode_Multiply ) );
+  QVERIFY( QgsAbstractGeoPdfExporter::compositionModeSupported( QPainter::CompositionMode_Screen ) );
+  QVERIFY( QgsAbstractGeoPdfExporter::compositionModeSupported( QPainter::CompositionMode_Overlay ) );
+  QVERIFY( QgsAbstractGeoPdfExporter::compositionModeSupported( QPainter::CompositionMode_Darken ) );
+  QVERIFY( QgsAbstractGeoPdfExporter::compositionModeSupported( QPainter::CompositionMode_Lighten ) );
+  QVERIFY( QgsAbstractGeoPdfExporter::compositionModeSupported( QPainter::CompositionMode_ColorDodge ) );
+  QVERIFY( QgsAbstractGeoPdfExporter::compositionModeSupported( QPainter::CompositionMode_ColorBurn ) );
+  QVERIFY( QgsAbstractGeoPdfExporter::compositionModeSupported( QPainter::CompositionMode_HardLight ) );
+  QVERIFY( QgsAbstractGeoPdfExporter::compositionModeSupported( QPainter::CompositionMode_SoftLight ) );
+  QVERIFY( QgsAbstractGeoPdfExporter::compositionModeSupported( QPainter::CompositionMode_Difference ) );
+  QVERIFY( QgsAbstractGeoPdfExporter::compositionModeSupported( QPainter::CompositionMode_Exclusion ) );
+  QVERIFY( !QgsAbstractGeoPdfExporter::compositionModeSupported( QPainter::CompositionMode_Plus ) );
+
+  QCOMPARE( QgsAbstractGeoPdfExporter::compositionModeToString( QPainter::CompositionMode_SourceOver ), QStringLiteral( "Normal" ) );
+  QCOMPARE( QgsAbstractGeoPdfExporter::compositionModeToString( QPainter::CompositionMode_Multiply ), QStringLiteral( "Multiply" ) );
+  QCOMPARE( QgsAbstractGeoPdfExporter::compositionModeToString( QPainter::CompositionMode_Screen ), QStringLiteral( "Screen" ) );
+  QCOMPARE( QgsAbstractGeoPdfExporter::compositionModeToString( QPainter::CompositionMode_Overlay ), QStringLiteral( "Overlay" ) );
+  QCOMPARE( QgsAbstractGeoPdfExporter::compositionModeToString( QPainter::CompositionMode_Darken ), QStringLiteral( "Darken" ) );
+  QCOMPARE( QgsAbstractGeoPdfExporter::compositionModeToString( QPainter::CompositionMode_Lighten ), QStringLiteral( "Lighten" ) );
+  QCOMPARE( QgsAbstractGeoPdfExporter::compositionModeToString( QPainter::CompositionMode_ColorDodge ), QStringLiteral( "ColorDodge" ) );
+  QCOMPARE( QgsAbstractGeoPdfExporter::compositionModeToString( QPainter::CompositionMode_ColorBurn ), QStringLiteral( "ColorBurn" ) );
+  QCOMPARE( QgsAbstractGeoPdfExporter::compositionModeToString( QPainter::CompositionMode_HardLight ), QStringLiteral( "HardLight" ) );
+  QCOMPARE( QgsAbstractGeoPdfExporter::compositionModeToString( QPainter::CompositionMode_SoftLight ), QStringLiteral( "SoftLight" ) );
+  QCOMPARE( QgsAbstractGeoPdfExporter::compositionModeToString( QPainter::CompositionMode_Difference ), QStringLiteral( "Difference" ) );
+  QCOMPARE( QgsAbstractGeoPdfExporter::compositionModeToString( QPainter::CompositionMode_Exclusion ), QStringLiteral( "Exclusion" ) );
+  QCOMPARE( QgsAbstractGeoPdfExporter::compositionModeToString( QPainter::CompositionMode_Plus ), QStringLiteral( "Normal" ) );
+}
+
 QGSTEST_MAIN( TestQgsGeoPdfExport )
 #include "testqgsgeopdfexport.moc"