diff --git a/decode.cpp b/decode.cpp
index ec039ec..2bf0d05 100644
--- a/decode.cpp
+++ b/decode.cpp
@@ -169,7 +169,8 @@ TeletextPageDecode::TeletextPageDecode()
 		m_rowHeight[r] = NormalHeight;
 		for (int c=0; c<72; c++) {
 			if (c < 40) {
-				m_cellLevel1Mosaic[r][c] = false;
+				m_cellLevel1MosaicAttr[r][c] = false;
+				m_cellLevel1MosaicChar[r][c] = false;
 				m_cellLevel1CharSet[r][c] = 0;
 			}
 			m_refresh[r][c] = true;
@@ -723,13 +724,18 @@ void TeletextPageDecode::decodeRow(int r)
 			}
 
 		// Level 1 character
+		if (c < 40) {
+			m_cellLevel1CharSet[r][c] = level1CharSet;
+			m_cellLevel1MosaicAttr[r][c] = level1Mosaics;
+			// Set to true on mosaic CHARACTER - not on blast through alphanumerics
+			m_cellLevel1MosaicChar[r][c] = level1Mosaics && (m_levelOnePage->character(r, c) & 0x20);
+		}
+
 		if (c < 40 && m_rowHeight[r] != BottomHalf) {
 			m_level1ActivePainter.result.character.diacritical = 0;
 			if (m_levelOnePage->character(r, c) >= 0x20) {
 				m_level1ActivePainter.result.character.code = m_levelOnePage->character(r, c);
-				// Set to true on mosaic character - not on blast through alphanumerics
-				m_cellLevel1Mosaic[r][c] = level1Mosaics && (m_levelOnePage->character(r, c) & 0x20);
-				if (m_cellLevel1Mosaic[r][c]) {
+				if (m_cellLevel1MosaicChar[r][c]) {
 					m_level1ActivePainter.result.character.set = 24 + (level1SeparatedMosaics || m_level1ActivePainter.attribute.display.underlineSeparated);
 					level1HoldMosaicCharacter = m_levelOnePage->character(r, c);
 					level1HoldMosaicSeparated = level1SeparatedMosaics;
@@ -743,9 +749,6 @@ void TeletextPageDecode::decodeRow(int r)
 			// In side panel or on bottom half of Level 1 double height row, no Level 1 characters here
 			m_level1ActivePainter.result.character = { 0x20, 0, 0 };
 
-		if (c < 40)
-			m_cellLevel1CharSet[r][c] = level1CharSet;
-
 		// X/26 characters
 
 		// Used to track if character was placed by X/26 data
diff --git a/decode.h b/decode.h
index a394fd0..8d5d878 100644
--- a/decode.h
+++ b/decode.h
@@ -64,7 +64,8 @@ public:
 	bool cellItalic(int r, int c) const { return m_cell[r][c].attribute.style.italic; };
 	bool cellProportional(int r, int c) const { return m_cell[r][c].attribute.style.proportional; };
 
-	bool level1MosaicAttribute(int r, int c) const { return m_cellLevel1Mosaic[r][c]; };
+	bool level1MosaicAttr(int r, int c) const { return m_cellLevel1MosaicAttr[r][c]; };
+	bool level1MosaicChar(int r, int c) const { return m_cellLevel1MosaicChar[r][c]; };
 	int level1CharSet(int r, int c) const { return m_cellLevel1CharSet[r][c]; };
 
 	RowHeight rowHeight(int r) const { return m_rowHeight[r]; };
@@ -261,7 +262,8 @@ private:
 
 	bool m_refresh[25][72];
 	textCell m_cell[25][72];
-	bool m_cellLevel1Mosaic[25][40];
+	bool m_cellLevel1MosaicAttr[25][40];
+	bool m_cellLevel1MosaicChar[25][40];
 	int m_cellLevel1CharSet[25][40];
 	LevelOnePage* m_levelOnePage;
 	int m_fullRowColour[25];
diff --git a/levelonecommands.cpp b/levelonecommands.cpp
index 09a35d0..1d3e8ed 100644
--- a/levelonecommands.cpp
+++ b/levelonecommands.cpp
@@ -149,12 +149,19 @@ bool TypeCharacterCommand::mergeWith(const QUndoCommand *command)
 ToggleMosaicBitCommand::ToggleMosaicBitCommand(TeletextDocument *teletextDocument, unsigned char bitToToggle, QUndoCommand *parent) : LevelOneCommand(teletextDocument, parent)
 {
 	m_oldCharacter = teletextDocument->currentSubPage()->character(m_row, m_column);
+
 	if (bitToToggle == 0x20 || bitToToggle == 0x7f)
+		// Clear or fill the whole mosaic character
 		m_newCharacter = bitToToggle;
 	else if (bitToToggle == 0x66)
+		// Dither
 		m_newCharacter = (m_row & 1) ? 0x66 : 0x39;
-	else
+	else if (m_oldCharacter & 0x20)
+		// Previous character was mosaic, just toggle the bit(s)
 		m_newCharacter = m_oldCharacter ^ bitToToggle;
+	else
+		// Previous character was blast-through, change to mosaic and set bit alone
+		m_newCharacter = bitToToggle | 0x20;
 
 	setText(QObject::tr("mosaic"));
 
diff --git a/mainwidget.cpp b/mainwidget.cpp
index d2a854c..e78fc9d 100644
--- a/mainwidget.cpp
+++ b/mainwidget.cpp
@@ -227,7 +227,7 @@ 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.level1MosaicAttribute(m_teletextDocument->cursorRow(), m_teletextDocument->cursorColumn()) && (mappedKeyPress < 0x40 || mappedKeyPress > 0x5f)) {
+		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 (event->key() >= Qt::Key_0 && event->key() <= Qt::Key_9 && event->modifiers() & Qt::KeypadModifier) {
 				switch (event->key()) {
@@ -406,7 +406,7 @@ void TeletextWidget::selectionToClipboard()
 			else
 				plainTextData.append(' ');
 
-			if (m_pageDecode.level1MosaicAttribute(r, c) && m_teletextDocument->currentSubPage()->character(r, c) & 0x20) {
+			if (m_pageDecode.level1MosaicChar(r, c)) {
 				// A first mosaic character was found so create the image "just in time"
 				if (imageData == nullptr) {
 					imageData = new QImage(m_teletextDocument->selectionWidth() * 2, m_teletextDocument->selectionHeight() * 3, QImage::Format_Mono);