diff --git a/src/qteletextmaker/levelonecommands.cpp b/src/qteletextmaker/levelonecommands.cpp
index 9936605..d9fc834 100644
--- a/src/qteletextmaker/levelonecommands.cpp
+++ b/src/qteletextmaker/levelonecommands.cpp
@@ -457,6 +457,49 @@ ShiftMosaicsRightCommand::ShiftMosaicsRightCommand(TeletextDocument *teletextDoc
 	setText(QObject::tr("shift mosaics right"));
 }
 
+FillMosaicsCommand::FillMosaicsCommand(TeletextDocument *teletextDocument, const QSet<QPair<int, int>> &mosaicList, QUndoCommand *parent) : ShiftMosaicsCommand(teletextDocument, mosaicList, parent)
+{
+	for (const auto &m : m_mosaicList)
+		m_newCharacters[m.first - m_selectionTopRow][m.second - m_selectionLeftColumn] = 0x7f;
+
+	setText(QObject::tr("fill mosaics"));
+}
+
+ClearMosaicsCommand::ClearMosaicsCommand(TeletextDocument *teletextDocument, const QSet<QPair<int, int>> &mosaicList, QUndoCommand *parent) : ShiftMosaicsCommand(teletextDocument, mosaicList, parent)
+{
+	for (const auto &m : m_mosaicList)
+		m_newCharacters[m.first - m_selectionTopRow][m.second - m_selectionLeftColumn] = 0x20;
+
+	setText(QObject::tr("clear mosaics"));
+}
+
+InvertMosaicsCommand::InvertMosaicsCommand(TeletextDocument *teletextDocument, const QSet<QPair<int, int>> &mosaicList, QUndoCommand *parent) : ShiftMosaicsCommand(teletextDocument, mosaicList, parent)
+{
+	for (const auto &m : m_mosaicList)
+		m_newCharacters[m.first - m_selectionTopRow][m.second - m_selectionLeftColumn] ^= 0x5f;
+
+	setText(QObject::tr("reverse mosaics"));
+}
+
+bool InvertMosaicsCommand::mergeWith(const QUndoCommand *command)
+{
+	const InvertMosaicsCommand *newerCommand = static_cast<const InvertMosaicsCommand *>(command);
+
+	if (m_subPageIndex != newerCommand->m_subPageIndex || m_selectionTopRow != newerCommand->m_selectionTopRow || m_selectionLeftColumn != newerCommand->m_selectionLeftColumn || m_selectionBottomRow != newerCommand->m_selectionBottomRow || m_selectionRightColumn != newerCommand->m_selectionRightColumn)
+		return false;
+
+	setObsolete(true);
+	return true;
+}
+
+DitherMosaicsCommand::DitherMosaicsCommand(TeletextDocument *teletextDocument, const QSet<QPair<int, int>> &mosaicList, QUndoCommand *parent) : ShiftMosaicsCommand(teletextDocument, mosaicList, parent)
+{
+	for (const auto &m : m_mosaicList)
+		m_newCharacters[m.first - m_selectionTopRow][m.second - m_selectionLeftColumn] = (m.first & 1) ? 0x66 : 0x39;
+
+	setText(QObject::tr("dither mosaics"));
+}
+
 
 InsertRowCommand::InsertRowCommand(TeletextDocument *teletextDocument, bool copyRow, QUndoCommand *parent) : LevelOneCommand(teletextDocument, parent)
 {
diff --git a/src/qteletextmaker/levelonecommands.h b/src/qteletextmaker/levelonecommands.h
index cf2e1ac..e0dbc65 100644
--- a/src/qteletextmaker/levelonecommands.h
+++ b/src/qteletextmaker/levelonecommands.h
@@ -164,6 +164,47 @@ public:
 	int id() const override { return Id; }
 };
 
+class FillMosaicsCommand : public ShiftMosaicsCommand
+{
+public:
+	enum { Id = 120 };
+
+	FillMosaicsCommand(TeletextDocument *teletextDocument, const QSet<QPair<int, int>> &mosaicList, QUndoCommand *parent = 0);
+
+	int id() const override { return Id; }
+};
+
+class ClearMosaicsCommand : public ShiftMosaicsCommand
+{
+public:
+	enum { Id = 121 };
+
+	ClearMosaicsCommand(TeletextDocument *teletextDocument, const QSet<QPair<int, int>> &mosaicList, QUndoCommand *parent = 0);
+
+	int id() const override { return Id; }
+};
+
+class InvertMosaicsCommand : public ShiftMosaicsCommand
+{
+public:
+	enum { Id = 122 };
+
+	InvertMosaicsCommand(TeletextDocument *teletextDocument, const QSet<QPair<int, int>> &mosaicList, QUndoCommand *parent = 0);
+
+	bool mergeWith(const QUndoCommand *command) override;
+	int id() const override { return Id; }
+};
+
+class DitherMosaicsCommand : public ShiftMosaicsCommand
+{
+public:
+	enum { Id = 123 };
+
+	DitherMosaicsCommand(TeletextDocument *teletextDocument, const QSet<QPair<int, int>> &mosaicList, QUndoCommand *parent = 0);
+
+	int id() const override { return Id; }
+};
+
 class InsertSubPageCommand : public LevelOneCommand
 {
 public:
diff --git a/src/qteletextmaker/mainwidget.cpp b/src/qteletextmaker/mainwidget.cpp
index 0d4eb6a..23f4269 100644
--- a/src/qteletextmaker/mainwidget.cpp
+++ b/src/qteletextmaker/mainwidget.cpp
@@ -228,8 +228,9 @@ void TeletextWidget::keyPressEvent(QKeyEvent *event)
 		// Map it to block character so it doesn't need to be inserted-between later on
 		if (mappedKeyPress & 0x80)
 			mappedKeyPress = 0x7f;
-		if (m_pageDecode.level1MosaicAttr(m_teletextDocument->cursorRow(), m_teletextDocument->cursorColumn()) && (mappedKeyPress < 0x40 || mappedKeyPress > 0x5f)) {
-			// We're on a mosaic and a blast-through character was NOT pressed
+		if ((m_pageDecode.level1MosaicAttr(m_teletextDocument->cursorRow(), m_teletextDocument->cursorColumn()) || m_teletextDocument->selectionActive()) && (mappedKeyPress < 0x40 || mappedKeyPress > 0x5f)) {
+			// A blast-through character was NOT pressed
+			// and we're either on a mosaic or a selection is active
 			if (event->key() >= Qt::Key_0 && event->key() <= Qt::Key_9 && event->modifiers() & Qt::KeypadModifier) {
 				switch (event->key()) {
 					case Qt::Key_7:
@@ -388,7 +389,27 @@ void TeletextWidget::setCharacter(unsigned char newCharacter)
 
 void TeletextWidget::toggleCharacterBit(unsigned char bitToToggle)
 {
-	m_teletextDocument->undoStack()->push(new ToggleMosaicBitCommand(m_teletextDocument, bitToToggle));
+	if (!m_teletextDocument->selectionActive())
+		m_teletextDocument->undoStack()->push(new ToggleMosaicBitCommand(m_teletextDocument, bitToToggle));
+	else {
+		const QSet<QPair<int, int>> mosaicList = findMosaics();
+
+		if (!mosaicList.isEmpty())
+			switch (bitToToggle) {
+				case 0x7f:
+					m_teletextDocument->undoStack()->push(new FillMosaicsCommand(m_teletextDocument, mosaicList));
+					break;
+				case 0x20:
+					m_teletextDocument->undoStack()->push(new ClearMosaicsCommand(m_teletextDocument, mosaicList));
+					break;
+				case 0x5f:
+					m_teletextDocument->undoStack()->push(new InvertMosaicsCommand(m_teletextDocument, mosaicList));
+					break;
+				case 0x66:
+					m_teletextDocument->undoStack()->push(new DitherMosaicsCommand(m_teletextDocument, mosaicList));
+					break;
+			}
+	}
 }
 
 QSet<QPair<int, int>> TeletextWidget::findMosaics()