diff --git a/doc/api_break.dox b/doc/api_break.dox
index d3abb00277a..1a21c64232b 100644
--- a/doc/api_break.dox
+++ b/doc/api_break.dox
@@ -615,6 +615,12 @@ Use the corresponding methods in QgsComposerUtils instead.
 instead.
 - lockSymbolSize(), imageSizeConsideringRotation(), cornerPointOnRotatedAndScaledRect(),
 sizeChangedByRotation() were removed. No replacement is offered for these methods.
+- transparency() and setTransparency() were removed. Use itemOpacity() and setItemOpacity() instead.
+
+QgsComposerItemCommand        {#qgis_api_break_3_0_QgsComposerItemCommand}
+----------------------
+
+- ItemTransparency was removed. Use ItemOpacity instead.
 
 
 QgsComposerLabel        {#qgis_api_break_3_0_QgsComposerLabel}
diff --git a/python/core/composer/qgscomposeritem.sip b/python/core/composer/qgscomposeritem.sip
index 5d0bc0fd71e..955b669a257 100644
--- a/python/core/composer/qgscomposeritem.sip
+++ b/python/core/composer/qgscomposeritem.sip
@@ -404,17 +404,8 @@ class QgsComposerItem : QgsComposerObject, QGraphicsRectItem
      */
     void setBlendMode( const QPainter::CompositionMode blendMode );
 
-    /** Returns the item's transparency
-     * @returns transparency as integer between 0 (transparent) and 255 (opaque)
-     * @see setTransparency
-     */
-    int transparency() const;
-
-    /** Sets the item's transparency
-     * @param transparency integer between 0 (transparent) and 255 (opaque)
-     * @see transparency
-     */
-    void setTransparency( const int transparency );
+    double itemOpacity() const;
+    void setItemOpacity( const double opacity );
 
     /** Returns whether effects (e.g., blend modes) are enabled for the item
      * @returns true if effects are enabled
diff --git a/python/core/composer/qgscomposeritemcommand.sip b/python/core/composer/qgscomposeritemcommand.sip
index 90aea99970a..8c5bb5195c1 100644
--- a/python/core/composer/qgscomposeritemcommand.sip
+++ b/python/core/composer/qgscomposeritemcommand.sip
@@ -112,7 +112,7 @@ class QgsComposerMergeCommand : QgsComposerItemCommand
       ItemBackgroundColor,
       ItemMove,
       ItemRotation,
-      ItemTransparency,
+      ItemOpacity,
       ItemZoomContent
     };
 
diff --git a/python/core/composer/qgscomposerobject.sip b/python/core/composer/qgscomposerobject.sip
index c547a7ede62..8a5603a2e8e 100644
--- a/python/core/composer/qgscomposerobject.sip
+++ b/python/core/composer/qgscomposerobject.sip
@@ -30,6 +30,7 @@ class QgsComposerObject : QObject, QgsExpressionContextGenerator
       ItemHeight, /*!< height of item */
       ItemRotation, /*!< rotation of item */
       Transparency, /*!< item transparency */
+      Opacity,
       BlendMode, /*!< item blend mode */
       ExcludeFromExports, /*!< exclude item from exports */
       FrameColor, //!< Item frame color
diff --git a/src/app/composer/qgscomposeritemwidget.cpp b/src/app/composer/qgscomposeritemwidget.cpp
index d23bf09f344..d218b0c34e0 100644
--- a/src/app/composer/qgscomposeritemwidget.cpp
+++ b/src/app/composer/qgscomposeritemwidget.cpp
@@ -170,7 +170,7 @@ QgsComposerItemWidget::QgsComposerItemWidget( QWidget *parent, QgsComposerItem *
   connect( mItem, &QgsComposerItem::sizeChanged, this, &QgsComposerItemWidget::setValuesForGuiPositionElements );
   connect( mItem, &QgsComposerObject::itemChanged, this, &QgsComposerItemWidget::setValuesForGuiNonPositionElements );
 
-  connect( mTransparencySlider, &QAbstractSlider::valueChanged, mTransparencySpnBx, &QSpinBox::setValue );
+  connect( mOpacitySlider, &QAbstractSlider::valueChanged, this, [ = ]( int value ) { mOpacitySpnBx->setValue( value / 10.0 ); } );
 
   updateVariables();
   connect( mVariableEditor, &QgsVariableEditorWidget::scopeChanged, this, &QgsComposerItemWidget::variablesChanged );
@@ -504,8 +504,8 @@ void QgsComposerItemWidget::setValuesForGuiNonPositionElements()
   mBackgroundGroupBox->blockSignals( true );
   mItemIdLineEdit->blockSignals( true );
   mBlendModeCombo->blockSignals( true );
-  mTransparencySlider->blockSignals( true );
-  mTransparencySpnBx->blockSignals( true );
+  mOpacitySlider->blockSignals( true );
+  mOpacitySpnBx->blockSignals( true );
   mFrameColorButton->blockSignals( true );
   mFrameJoinStyleCombo->blockSignals( true );
   mBackgroundColorButton->blockSignals( true );
@@ -520,8 +520,8 @@ void QgsComposerItemWidget::setValuesForGuiNonPositionElements()
   mFrameGroupBox->setChecked( mItem->hasFrame() );
   mBackgroundGroupBox->setChecked( mItem->hasBackground() );
   mBlendModeCombo->setBlendMode( mItem->blendMode() );
-  mTransparencySlider->setValue( mItem->transparency() );
-  mTransparencySpnBx->setValue( mItem->transparency() );
+  mOpacitySlider->setValue( mItem->itemOpacity() * 1000.0 );
+  mOpacitySpnBx->setValue( mItem->itemOpacity() * 100.0 );
   mItemRotationSpinBox->setValue( mItem->itemRotation( QgsComposerObject::OriginalValue ) );
   mExcludeFromPrintsCheckBox->setChecked( mItem->excludeFromExports( QgsComposerObject::OriginalValue ) );
 
@@ -533,8 +533,8 @@ void QgsComposerItemWidget::setValuesForGuiNonPositionElements()
   mBackgroundGroupBox->blockSignals( false );
   mItemIdLineEdit->blockSignals( false );
   mBlendModeCombo->blockSignals( false );
-  mTransparencySlider->blockSignals( false );
-  mTransparencySpnBx->blockSignals( false );
+  mOpacitySlider->blockSignals( false );
+  mOpacitySpnBx->blockSignals( false );
   mItemRotationSpinBox->blockSignals( false );
   mExcludeFromPrintsCheckBox->blockSignals( false );
 }
@@ -546,7 +546,7 @@ void QgsComposerItemWidget::initializeDataDefinedButtons()
   mConfigObject->initializeDataDefinedButton( mWidthDDBtn, QgsComposerObject::ItemWidth );
   mConfigObject->initializeDataDefinedButton( mHeightDDBtn, QgsComposerObject::ItemHeight );
   mConfigObject->initializeDataDefinedButton( mItemRotationDDBtn, QgsComposerObject::ItemRotation );
-  mConfigObject->initializeDataDefinedButton( mTransparencyDDBtn, QgsComposerObject::Transparency );
+  mConfigObject->initializeDataDefinedButton( mOpacityDDBtn, QgsComposerObject::Opacity );
   mConfigObject->initializeDataDefinedButton( mBlendModeDDBtn, QgsComposerObject::BlendMode );
   mConfigObject->initializeDataDefinedButton( mExcludePrintsDDBtn, QgsComposerObject::ExcludeFromExports );
   mConfigObject->initializeDataDefinedButton( mItemFrameColorDDBtn, QgsComposerObject::FrameColor );
@@ -591,15 +591,15 @@ void QgsComposerItemWidget::on_mBlendModeCombo_currentIndexChanged( int index )
   }
 }
 
-void QgsComposerItemWidget::on_mTransparencySpnBx_valueChanged( int value )
+void QgsComposerItemWidget::on_mOpacitySpnBx_valueChanged( double value )
 {
-  mTransparencySlider->blockSignals( true );
-  mTransparencySlider->setValue( value );
-  mTransparencySlider->blockSignals( false );
+  mOpacitySlider->blockSignals( true );
+  mOpacitySlider->setValue( value * 10 );
+  mOpacitySlider->blockSignals( false );
   if ( mItem )
   {
-    mItem->beginCommand( tr( "Item transparency changed" ), QgsComposerMergeCommand::ItemTransparency );
-    mItem->setTransparency( value );
+    mItem->beginCommand( tr( "Item opacity changed" ), QgsComposerMergeCommand::ItemOpacity );
+    mItem->setItemOpacity( value / 100.0 );
     mItem->endCommand();
   }
 }
diff --git a/src/app/composer/qgscomposeritemwidget.h b/src/app/composer/qgscomposeritemwidget.h
index 71cc3abf436..bd8f3623aec 100644
--- a/src/app/composer/qgscomposeritemwidget.h
+++ b/src/app/composer/qgscomposeritemwidget.h
@@ -172,7 +172,7 @@ class QgsComposerItemWidget: public QWidget, private Ui::QgsComposerItemWidgetBa
     void on_mLowerRightCheckBox_stateChanged( int state );
 
     void on_mBlendModeCombo_currentIndexChanged( int index );
-    void on_mTransparencySpnBx_valueChanged( int value );
+    void on_mOpacitySpnBx_valueChanged( double value );
 
     void on_mItemRotationSpinBox_valueChanged( double val );
     void on_mExcludeFromPrintsCheckBox_toggled( bool checked );
diff --git a/src/core/composer/qgscomposeritem.cpp b/src/core/composer/qgscomposeritem.cpp
index af839011f71..fd296b55f03 100644
--- a/src/core/composer/qgscomposeritem.cpp
+++ b/src/core/composer/qgscomposeritem.cpp
@@ -60,7 +60,6 @@ QgsComposerItem::QgsComposerItem( QgsComposition *composition, bool manageZValue
   , mEvaluatedItemRotation( 0 )
   , mBlendMode( QPainter::CompositionMode_SourceOver )
   , mEffectsEnabled( true )
-  , mTransparency( 0 )
   , mExcludeFromExports( false )
   , mEvaluatedExcludeFromExports( false )
   , mLastUsedPositionMode( UpperLeft )
@@ -89,7 +88,6 @@ QgsComposerItem::QgsComposerItem( qreal x, qreal y, qreal width, qreal height, Q
   , mEvaluatedItemRotation( 0 )
   , mBlendMode( QPainter::CompositionMode_SourceOver )
   , mEffectsEnabled( true )
-  , mTransparency( 0 )
   , mExcludeFromExports( false )
   , mEvaluatedExcludeFromExports( false )
   , mLastUsedPositionMode( UpperLeft )
@@ -228,8 +226,8 @@ bool QgsComposerItem::_writeXml( QDomElement &itemElem, QDomDocument &doc ) cons
   //blend mode
   composerItemElem.setAttribute( QStringLiteral( "blendMode" ), QgsPainting::getBlendModeEnum( mBlendMode ) );
 
-  //transparency
-  composerItemElem.setAttribute( QStringLiteral( "transparency" ), QString::number( mTransparency ) );
+  //opacity
+  composerItemElem.setAttribute( QStringLiteral( "opacity" ), QString::number( mOpacity ) );
 
   composerItemElem.setAttribute( QStringLiteral( "excludeFromExports" ), mExcludeFromExports );
 
@@ -386,8 +384,15 @@ bool QgsComposerItem::_readXml( const QDomElement &itemElem, const QDomDocument
   //blend mode
   setBlendMode( QgsPainting::getCompositionMode( static_cast< QgsPainting::BlendMode >( itemElem.attribute( QStringLiteral( "blendMode" ), QStringLiteral( "0" ) ).toUInt() ) ) );
 
-  //transparency
-  setTransparency( itemElem.attribute( QStringLiteral( "transparency" ), QStringLiteral( "0" ) ).toInt() );
+  //opacity
+  if ( itemElem.hasAttribute( QStringLiteral( "opacity" ) ) )
+  {
+    setItemOpacity( itemElem.attribute( QStringLiteral( "opacity" ), QStringLiteral( "1" ) ).toDouble() );
+  }
+  else
+  {
+    setItemOpacity( 1.0 - itemElem.attribute( QStringLiteral( "transparency" ), QStringLiteral( "0" ) ).toInt() / 100.0 );
+  }
 
   mExcludeFromExports = itemElem.attribute( QStringLiteral( "excludeFromExports" ), QStringLiteral( "0" ) ).toInt();
   mEvaluatedExcludeFromExports = mExcludeFromExports;
@@ -895,20 +900,20 @@ void QgsComposerItem::refreshBlendMode( const QgsExpressionContext &context )
   mEffect->setCompositionMode( blendMode );
 }
 
-void QgsComposerItem::setTransparency( const int transparency )
+void QgsComposerItem::setItemOpacity( const double opacity )
 {
-  mTransparency = transparency;
+  mOpacity = opacity;
   QgsExpressionContext context = createExpressionContext();
-  refreshTransparency( true, context );
+  refreshOpacity( true, context );
 }
 
-void QgsComposerItem::refreshTransparency( const bool updateItem, const QgsExpressionContext &context )
+void QgsComposerItem::refreshOpacity( const bool updateItem, const QgsExpressionContext &context )
 {
-  //data defined transparency set?
-  int transparency = mDataDefinedProperties.valueAsInt( QgsComposerObject::Transparency, context, mTransparency );
+  //data defined opacity set?
+  double opacity = mDataDefinedProperties.valueAsDouble( QgsComposerObject::Opacity, context, mOpacity * 100.0 );
 
   // Set the QGraphicItem's opacity
-  setOpacity( 1. - ( transparency / 100. ) );
+  setOpacity( opacity / 100.0 );
 
   if ( updateItem )
   {
@@ -1140,9 +1145,9 @@ void QgsComposerItem::refreshDataDefinedProperty( const QgsComposerObject::DataD
   {
     refreshRotation( false, true, *evalContext );
   }
-  if ( property == QgsComposerObject::Transparency || property == QgsComposerObject::AllProperties )
+  if ( property == QgsComposerObject::Opacity || property == QgsComposerObject::AllProperties )
   {
-    refreshTransparency( false, *evalContext );
+    refreshOpacity( false, *evalContext );
   }
   if ( property == QgsComposerObject::BlendMode || property == QgsComposerObject::AllProperties )
   {
diff --git a/src/core/composer/qgscomposeritem.h b/src/core/composer/qgscomposeritem.h
index b5cbd5218d4..32df6ac1e19 100644
--- a/src/core/composer/qgscomposeritem.h
+++ b/src/core/composer/qgscomposeritem.h
@@ -364,22 +364,26 @@ class CORE_EXPORT QgsComposerItem: public QgsComposerObject, public QGraphicsRec
      */
     void setBlendMode( const QPainter::CompositionMode blendMode );
 
-    /** Returns the item's transparency
-     * \returns transparency as integer between 0 (transparent) and 255 (opaque)
-     * \see setTransparency
+    /** Returns the item's opacity. This method should be used instead of
+     * QGraphicsItem::opacity() as any data defined overrides will be
+     * respected.
+     * \returns opacity as double between 1.0 (opaque) and 0 (transparent).
+     * \see setItemOpacity()
      */
-    int transparency() const { return mTransparency; }
+    double itemOpacity() const { return mOpacity; }
 
-    /** Sets the item's transparency
-     * \param transparency integer between 0 (transparent) and 255 (opaque)
-     * \see transparency
+    /** Sets the item's \a opacity. This method should be used instead of
+     * QGraphicsItem::setOpacity() as any data defined overrides will be
+     * respected.
+     * \param opacity double between 1.0 (opaque) and 0 (transparent).
+     * \see itemOpacity()
      */
-    void setTransparency( const int transparency );
+    void setItemOpacity( const double itemOpacity );
 
     /** Returns whether effects (e.g., blend modes) are enabled for the item
      * \returns true if effects are enabled
      * \see setEffectsEnabled
-     * \see transparency
+     * \see itemOpacity()
      * \see blendMode
      */
     bool effectsEnabled() const { return mEffectsEnabled; }
@@ -387,7 +391,7 @@ class CORE_EXPORT QgsComposerItem: public QgsComposerObject, public QGraphicsRec
     /** Sets whether effects (e.g., blend modes) are enabled for the item
      * \param effectsEnabled set to true to enable effects
      * \see effectsEnabled
-     * \see setTransparency
+     * \see setItemOpacity()
      * \see setBlendMode
      */
     void setEffectsEnabled( const bool effectsEnabled );
@@ -621,8 +625,8 @@ class CORE_EXPORT QgsComposerItem: public QgsComposerObject, public QGraphicsRec
     bool mEffectsEnabled;
     QgsComposerEffect *mEffect = nullptr;
 
-    //! Item transparency
-    int mTransparency;
+    //! Item opacity, between 0 and 1
+    double mOpacity = 1.0;
 
     //! Whether item should be excluded in exports
     bool mExcludeFromExports;
@@ -734,25 +738,25 @@ class CORE_EXPORT QgsComposerItem: public QgsComposerObject, public QGraphicsRec
      */
     void refreshRotation( const bool updateItem = true, const bool rotateAroundCenter = false, const QgsExpressionContext &context = QgsExpressionContext() );
 
-    /** Refresh item's transparency, considering data defined transparency
+    /** Refresh item's opacity, considering data defined opacity
       * \param updateItem set to false to prevent the item being automatically updated
-      * after the transparency is set
-      * \param context expression context for evaulating data defined transparency
+      * after the opacity is set
+      * \param context expression context for evaulating data defined opacity
       * \since QGIS 2.5
      */
-    void refreshTransparency( const bool updateItem = true, const QgsExpressionContext &context = QgsExpressionContext() );
+    void refreshOpacity( const bool updateItem = true, const QgsExpressionContext &context = QgsExpressionContext() );
 
-    /** Refresh item's frame color, considering data defined transparency
+    /** Refresh item's frame color, considering data defined colors
       * \param updateItem set to false to prevent the item being automatically updated
       * after the frame color is set
-      * \param context expression context for evaulating data defined transparency
+      * \param context expression context for evaulating data defined color
      */
     void refreshFrameColor( const bool updateItem = true, const QgsExpressionContext &context = QgsExpressionContext() );
 
-    /** Refresh item's transparency, considering data defined transparency
+    /** Refresh item's background color, considering data defined colors
       * \param updateItem set to false to prevent the item being automatically updated
       * after the background color is set
-      * \param context expression context for evaulating data defined transparency
+      * \param context expression context for evaulating data defined color
      */
     void refreshBackgroundColor( const bool updateItem = true, const QgsExpressionContext &context = QgsExpressionContext() );
 
diff --git a/src/core/composer/qgscomposeritemcommand.h b/src/core/composer/qgscomposeritemcommand.h
index 833eb88710b..464b1e02f0b 100644
--- a/src/core/composer/qgscomposeritemcommand.h
+++ b/src/core/composer/qgscomposeritemcommand.h
@@ -154,7 +154,7 @@ class CORE_EXPORT QgsComposerMergeCommand: public QgsComposerItemCommand
       ItemBackgroundColor,
       ItemMove,
       ItemRotation,
-      ItemTransparency,
+      ItemOpacity, //!< Item opacity
       ItemZoomContent
     };
 
diff --git a/src/core/composer/qgscomposermultiframe.cpp b/src/core/composer/qgscomposermultiframe.cpp
index 55af8b056d4..7a131956016 100644
--- a/src/core/composer/qgscomposermultiframe.cpp
+++ b/src/core/composer/qgscomposermultiframe.cpp
@@ -213,7 +213,7 @@ QgsComposerFrame *QgsComposerMultiFrame::createNewFrame( QgsComposerFrame *curre
   newFrame->setFrameStrokeColor( currentFrame->frameStrokeColor() );
   newFrame->setFrameJoinStyle( currentFrame->frameJoinStyle() );
   newFrame->setFrameStrokeWidth( currentFrame->frameStrokeWidth() );
-  newFrame->setTransparency( currentFrame->transparency() );
+  newFrame->setItemOpacity( currentFrame->itemOpacity() );
   newFrame->setHideBackgroundIfEmpty( currentFrame->hideBackgroundIfEmpty() );
 
   addFrame( newFrame, false );
diff --git a/src/core/composer/qgscomposerobject.cpp b/src/core/composer/qgscomposerobject.cpp
index 44f81a6b8d0..ecd8a2ca7a7 100644
--- a/src/core/composer/qgscomposerobject.cpp
+++ b/src/core/composer/qgscomposerobject.cpp
@@ -51,6 +51,7 @@ void QgsComposerObject::initPropertyDefinitions()
     { QgsComposerObject::ItemHeight, QgsPropertyDefinition( "dataDefinedHeight", QObject::tr( "Height" ), QgsPropertyDefinition::DoublePositive ) },
     { QgsComposerObject::ItemRotation, QgsPropertyDefinition( "dataDefinedRotation", QObject::tr( "Rotation angle" ), QgsPropertyDefinition::Rotation ) },
     { QgsComposerObject::Transparency, QgsPropertyDefinition( "dataDefinedTransparency", QObject::tr( "Transparency" ), QgsPropertyDefinition::Transparency ) },
+    { QgsComposerObject::Opacity, QgsPropertyDefinition( "dataDefinedOpacity", QObject::tr( "Opacity" ), QgsPropertyDefinition::Transparency ) },
     { QgsComposerObject::BlendMode, QgsPropertyDefinition( "dataDefinedBlendMode", QObject::tr( "Blend mode" ), QgsPropertyDefinition::BlendMode ) },
     { QgsComposerObject::ExcludeFromExports, QgsPropertyDefinition( "dataDefinedExcludeExports", QObject::tr( "Exclude item from exports" ), QgsPropertyDefinition::Boolean ) },
     { QgsComposerObject::FrameColor, QgsPropertyDefinition( "dataDefinedFrameColor", QObject::tr( "Frame color" ), QgsPropertyDefinition::ColorWithAlpha ) },
@@ -142,6 +143,14 @@ bool QgsComposerObject::readXml( const QDomElement &itemElem, const QDomDocument
   {
     mDataDefinedProperties.readXml( propsNode.toElement(), sPropertyDefinitions );
   }
+  if ( mDataDefinedProperties.isActive( QgsComposerObject::Transparency ) )
+  {
+    // upgrade transparency -> opacity
+    QString exp = mDataDefinedProperties.property( QgsComposerObject::Transparency ).asExpression();
+    exp = QStringLiteral( "100.0 - (%1)" ).arg( exp );
+    mDataDefinedProperties.setProperty( QgsComposerObject::Opacity, QgsProperty::fromExpression( exp ) );
+    mDataDefinedProperties.setProperty( QgsComposerObject::Transparency, QgsProperty() );
+  }
 
   //custom properties
   mCustomProperties.readXml( itemElem );
diff --git a/src/core/composer/qgscomposerobject.h b/src/core/composer/qgscomposerobject.h
index 092f5fe1f0a..d43bf96a116 100644
--- a/src/core/composer/qgscomposerobject.h
+++ b/src/core/composer/qgscomposerobject.h
@@ -57,7 +57,8 @@ class CORE_EXPORT QgsComposerObject: public QObject, public QgsExpressionContext
       ItemWidth, //!< Width of item
       ItemHeight, //!< Height of item
       ItemRotation, //!< Rotation of item
-      Transparency, //!< Item transparency
+      Transparency, //!< Item transparency (deprecated)
+      Opacity, //!< Item opacity
       BlendMode, //!< Item blend mode
       ExcludeFromExports, //!< Exclude item from exports
       FrameColor, //!< Item frame color
diff --git a/src/ui/composer/qgscomposeritemwidgetbase.ui b/src/ui/composer/qgscomposeritemwidgetbase.ui
index 5b8b5f5eaca..1feda70afa4 100644
--- a/src/ui/composer/qgscomposeritemwidgetbase.ui
+++ b/src/ui/composer/qgscomposeritemwidgetbase.ui
@@ -6,8 +6,8 @@
    <rect>
     <x>0</x>
     <y>0</y>
-    <width>290</width>
-    <height>1017</height>
+    <width>309</width>
+    <height>1135</height>
    </rect>
   </property>
   <property name="windowTitle">
@@ -658,37 +658,55 @@
       <item row="1" column="0">
        <widget class="QLabel" name="labelTransparency">
         <property name="text">
-         <string>Transparency</string>
+         <string>Opacity</string>
         </property>
        </widget>
       </item>
       <item row="1" column="1">
        <layout class="QHBoxLayout" name="horizontalLayout_2">
         <item>
-         <widget class="QSlider" name="mTransparencySlider">
+         <widget class="QSlider" name="mOpacitySlider">
           <property name="maximum">
+           <number>1000</number>
+          </property>
+          <property name="singleStep">
+           <number>10</number>
+          </property>
+          <property name="pageStep">
            <number>100</number>
           </property>
+          <property name="value">
+           <number>1000</number>
+          </property>
           <property name="orientation">
            <enum>Qt::Horizontal</enum>
           </property>
          </widget>
         </item>
         <item>
-         <widget class="QgsSpinBox" name="mTransparencySpnBx">
+         <widget class="QgsDoubleSpinBox" name="mOpacitySpnBx">
           <property name="minimumSize">
            <size>
-            <width>80</width>
+            <width>100</width>
             <height>25</height>
            </size>
           </property>
+          <property name="suffix">
+           <string> %</string>
+          </property>
+          <property name="decimals">
+           <number>1</number>
+          </property>
           <property name="maximum">
-           <number>100</number>
+           <double>100.000000000000000</double>
+          </property>
+          <property name="value">
+           <double>100.000000000000000</double>
           </property>
          </widget>
         </item>
         <item>
-         <widget class="QgsPropertyOverrideButton" name="mTransparencyDDBtn">
+         <widget class="QgsPropertyOverrideButton" name="mOpacityDDBtn">
           <property name="text">
            <string>...</string>
           </property>
@@ -841,9 +859,9 @@
   <tabstop>groupRendering</tabstop>
   <tabstop>mBlendModeCombo</tabstop>
   <tabstop>mBlendModeDDBtn</tabstop>
-  <tabstop>mTransparencySlider</tabstop>
-  <tabstop>mTransparencySpnBx</tabstop>
-  <tabstop>mTransparencyDDBtn</tabstop>
+  <tabstop>mOpacitySlider</tabstop>
+  <tabstop>mOpacitySpnBx</tabstop>
+  <tabstop>mOpacityDDBtn</tabstop>
   <tabstop>mExcludeFromPrintsCheckBox</tabstop>
   <tabstop>mExcludePrintsDDBtn</tabstop>
  </tabstops>
diff --git a/tests/src/core/testqgscomposereffects.cpp b/tests/src/core/testqgscomposereffects.cpp
index 81b2ac44a3b..690d5d4cb78 100644
--- a/tests/src/core/testqgscomposereffects.cpp
+++ b/tests/src/core/testqgscomposereffects.cpp
@@ -111,7 +111,7 @@ void TestQgsComposerEffects::blend_modes()
 
 void TestQgsComposerEffects::transparency()
 {
-  mComposerRect2->setTransparency( 50 );
+  mComposerRect2->setItemOpacity( 0.5 );
 
   QgsCompositionChecker checker( QStringLiteral( "composereffects_transparency" ), mComposition );
   checker.setControlPathPrefix( QStringLiteral( "composer_effects" ) );
diff --git a/tests/src/core/testqgscomposermultiframe.cpp b/tests/src/core/testqgscomposermultiframe.cpp
index ef5bb9376fb..6f96f3d7060 100644
--- a/tests/src/core/testqgscomposermultiframe.cpp
+++ b/tests/src/core/testqgscomposermultiframe.cpp
@@ -109,7 +109,7 @@ void TestQgsComposerMultiFrame::addFrame()
   frame1->setBackgroundEnabled( true );
   frame1->setBackgroundColor( QColor( Qt::green ) );
   frame1->setBlendMode( QPainter::CompositionMode_ColorBurn );
-  frame1->setTransparency( 50 );
+  frame1->setItemOpacity( 0.5 );
 
   QgsComposerFrame *frame2 = htmlItem->createNewFrame( frame1, QPointF( 50, 55 ), QSizeF( 70, 120 ) );
 
@@ -126,7 +126,7 @@ void TestQgsComposerMultiFrame::addFrame()
   QCOMPARE( frame2->hasBackground(), frame1->hasBackground() );
   QCOMPARE( frame2->backgroundColor(), frame1->backgroundColor() );
   QCOMPARE( frame2->blendMode(), frame1->blendMode() );
-  QCOMPARE( frame2->transparency(), frame1->transparency() );
+  QCOMPARE( frame2->itemOpacity(), frame1->itemOpacity() );
 
   //check non-inherited properties
   QVERIFY( !frame2->hidePageIfEmpty() );
@@ -252,10 +252,10 @@ void TestQgsComposerMultiFrame::undoRedo()
   mComposition->endMultiFrameCommand();
 
   //another frame command
-  frame1->beginCommand( QStringLiteral( "bgcolor" ), QgsComposerMergeCommand::ItemTransparency );
+  frame1->beginCommand( QStringLiteral( "bgcolor" ), QgsComposerMergeCommand::ItemOpacity );
   frame1->setBackgroundColor( QColor( 255, 255, 0 ) );
   frame1->endCommand();
-  frame1->beginCommand( QStringLiteral( "bgcolor" ), QgsComposerMergeCommand::ItemTransparency );
+  frame1->beginCommand( QStringLiteral( "bgcolor" ), QgsComposerMergeCommand::ItemOpacity );
   frame1->setBackgroundColor( QColor( 255, 0, 0 ) );
   frame1->endCommand();