diff --git a/uk/ac/babraham/FastQC/Utilities/ImageSaver/SVGGenerator.java b/uk/ac/babraham/FastQC/Utilities/ImageSaver/SVGGenerator.java
index 4f6cebf..eec7360 100644
--- a/uk/ac/babraham/FastQC/Utilities/ImageSaver/SVGGenerator.java
+++ b/uk/ac/babraham/FastQC/Utilities/ImageSaver/SVGGenerator.java
@@ -134,6 +134,7 @@ private SVGGenerator (StringBuffer sb, Component c) {
 		sb.append("\" height=\"");
 		sb.append(c.getHeight());
 		sb.append("\" version=\"1.1\" xmlns=\"http://www.w3.org/2000/svg\">\n");
+		sb.append("<style>text{font-family:Arial}</style>\n");
 
 		c.paint(new SVGGraphics());
 
@@ -237,7 +238,7 @@ public void drawLine(int x1, int y1, int x2, int y2) {
 			sb.append(y2);
 			sb.append("\" stroke=\"rgb(");
 			appendColor();
-			sb.append(")\" stroke-width=\"1\"/>\n");
+			sb.append(")\" stroke-width=\"2\"/>\n");
 		}
 	
 		/* (non-Javadoc)
@@ -273,9 +274,9 @@ public void drawOval(int x, int y, int width, int height) {
 			sb.append(width);
 			sb.append("\" ry=\"");
 			sb.append(height);
-			sb.append("\" style=\"fill:none;stroke:rgb(");
+			sb.append("\" fill=\"none\" stroke=\"rgb(");
 			appendColor();
-			sb.append(");stroke-width:1\"/>\n");
+			sb.append(")\"/>\n");
 		}
 		
 		/* (non-Javadoc)
@@ -311,9 +312,9 @@ public void fillOval(int x, int y, int width, int height) {
 			sb.append(width);
 			sb.append("\" ry=\"");
 			sb.append(height);
-			sb.append("\" style=\"fill:rgb(");
+			sb.append("\" fill=\"rgb(");
 			appendColor();
-			sb.append(");stroke:none\"/>\n");
+			sb.append(")\"/>\n");
 		}
 	
 		/* (non-Javadoc)
@@ -344,7 +345,7 @@ public void drawString(String string, int x, int y) {
 			sb.append(y);
 			sb.append("\" fill=\"rgb(");
 			appendColor();
-			sb.append(")\" font-family=\"Arial\" font-size=\"");
+			sb.append(")\" font-size=\"");
 			sb.append(font.getSize());
 			if (font.isBold()) {
 				sb.append("\" font-weight=\"bold");
@@ -404,8 +405,7 @@ public void drawRoundRect(int x, int y, int width, int height, int arcWidth,int
 			sb.append(arcWidth);
 			sb.append("\" ry=\"");
 			sb.append(arcHeight);
-			sb.append("\" style=\"fill:none");
-			sb.append(";stroke-width:1;stroke:rgb(");
+			sb.append("\" fill=\"none\" stroke=\"rgb(");
 					
 			appendColor();
 					
@@ -450,11 +450,11 @@ public void fillRoundRect(int x, int y, int width, int height, int arcWidth,int
 				sb.append("\" ry=\"");
 				sb.append(arcHeight);
 			}
-			sb.append("\" style=\"fill:rgb(");
+			sb.append("\" fill=\"rgb(");
 			
 			appendColor();
 	
-			sb.append(");stroke:none\"/>\n");
+			sb.append(")\"/>\n");
 		}
 		
 		/* (non-Javadoc)
@@ -607,11 +607,11 @@ public void drawPolygon(int[] xPoints, int[] yPoints, int pointsToUse) {
 				sb.append(correctedYPoints[i]);
 			}
 			
-			sb.append("\" style=\"stroke-width:1;stroke:rgb(");
+			sb.append("\" fill=\"none\" stroke=\"rgb(");
 			
 			appendColor();
 	
-			sb.append(");fill:none\"/>\n");
+			sb.append(")\"/>\n");
 		}
 	
 		/* (non-Javadoc)
@@ -661,11 +661,11 @@ public void fillPolygon(int[] xPoints, int[] yPoints, int pointsToUse) {
 				sb.append(correctedYPoints[i]);
 			}
 			
-			sb.append("\" style=\"fill:rgb(");
+			sb.append("\" fill=\"rgb(");
 			
 			appendColor();
 	
-			sb.append(");stroke:none\"/>\n");
+			sb.append(")\"/>\n");
 
 		}
 	
diff --git a/uk/ac/babraham/FastQC/Utilities/ImageSaver/SVGImageSaver.java b/uk/ac/babraham/FastQC/Utilities/ImageSaver/SVGImageSaver.java
index 5e4443f..7dd244f 100644
--- a/uk/ac/babraham/FastQC/Utilities/ImageSaver/SVGImageSaver.java
+++ b/uk/ac/babraham/FastQC/Utilities/ImageSaver/SVGImageSaver.java
@@ -22,6 +22,9 @@
 import java.awt.Component;
 import java.io.OutputStream;
 import java.io.PrintWriter;
+import java.util.ArrayList;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
 
 
 /**
@@ -31,14 +34,135 @@
  */
 public class SVGImageSaver {
 
+	private static final Pattern LINE_PATTERN = Pattern.compile(
+		"<line x1=\"(\\d+)\" y1=\"(\\d+)\" x2=\"(\\d+)\" y2=\"(\\d+)\" stroke=\"(rgb\\([^)]+\\))\" stroke-width=\"(\\d+)\"/>"
+	);
+
+	private static final Pattern RECT_PATTERN = Pattern.compile(
+		"<rect width=\"(\\d+)\" height=\"(\\d+)\" x=\"(\\d+)\" y=\"(\\d+)\" fill=\"(rgb\\([^)]+\\))\"/>"
+	);
+
 	public static String saveImage (Component c, OutputStream os) {
 		PrintWriter pr = new PrintWriter(os);
 		String svgData = SVGGenerator.writeSVG(c);
+		svgData = optimizeSvg(svgData);
 		pr.write(svgData);
 		pr.flush();
 		return(svgData);
 	}
-	
-	
-			
+
+	private static String optimizeSvg(String svg) {
+		svg = mergeLinesToPolylines(svg);
+		svg = mergeRects(svg);
+		return svg;
+	}
+
+	/** Merge consecutive same-colour line elements into polyline elements. */
+	private static String mergeLinesToPolylines(String svg) {
+		String[] lines = svg.split("\n");
+		StringBuilder result = new StringBuilder(svg.length());
+		ArrayList<String[]> group = new ArrayList<>();
+		String groupStroke = null;
+		String groupWidth = null;
+
+		for (String line : lines) {
+			Matcher m = LINE_PATTERN.matcher(line.trim());
+			if (m.matches()) {
+				String stroke = m.group(5);
+				String width = m.group(6);
+				if ("rgb(0,0,0)".equals(stroke) || "rgb(180,180,180)".equals(stroke)) {
+					flushLineGroup(result, group, groupStroke, groupWidth);
+					group.clear();
+					groupStroke = null;
+					result.append(line).append("\n");
+				} else if (stroke.equals(groupStroke) && width.equals(groupWidth)) {
+					group.add(new String[]{m.group(1), m.group(2), m.group(3), m.group(4)});
+				} else {
+					flushLineGroup(result, group, groupStroke, groupWidth);
+					group.clear();
+					groupStroke = stroke;
+					groupWidth = width;
+					group.add(new String[]{m.group(1), m.group(2), m.group(3), m.group(4)});
+				}
+			} else {
+				flushLineGroup(result, group, groupStroke, groupWidth);
+				group.clear();
+				groupStroke = null;
+				result.append(line).append("\n");
+			}
+		}
+		flushLineGroup(result, group, groupStroke, groupWidth);
+		return result.toString();
+	}
+
+	private static void flushLineGroup(StringBuilder sb, ArrayList<String[]> group, String stroke, String width) {
+		if (group.size() <= 2) {
+			for (String[] seg : group) {
+				sb.append("<line x1=\"").append(seg[0]).append("\" y1=\"").append(seg[1])
+				  .append("\" x2=\"").append(seg[2]).append("\" y2=\"").append(seg[3])
+				  .append("\" stroke=\"").append(stroke).append("\" stroke-width=\"").append(width)
+				  .append("\"/>\n");
+			}
+			return;
+		}
+		StringBuilder points = new StringBuilder();
+		points.append(group.get(0)[0]).append(",").append(group.get(0)[1]);
+		for (String[] seg : group) {
+			points.append(" ").append(seg[2]).append(",").append(seg[3]);
+		}
+		sb.append("<polyline points=\"").append(points)
+		  .append("\" stroke=\"").append(stroke).append("\" stroke-width=\"").append(width)
+		  .append("\" fill=\"none\"/>\n");
+	}
+
+	/** Merge consecutive same-colour filled rects on the same row into wider rects. */
+	private static String mergeRects(String svg) {
+		String[] lines = svg.split("\n");
+		StringBuilder result = new StringBuilder(svg.length());
+		ArrayList<int[]> group = new ArrayList<>();
+		String groupFill = null;
+
+		for (String line : lines) {
+			Matcher m = RECT_PATTERN.matcher(line.trim());
+			if (m.matches()) {
+				int w = Integer.parseInt(m.group(1));
+				int h = Integer.parseInt(m.group(2));
+				int x = Integer.parseInt(m.group(3));
+				int y = Integer.parseInt(m.group(4));
+				String fill = m.group(5);
+				if (w > 100 || h > 100) {
+					flushRectGroup(result, group, groupFill);
+					group.clear();
+					groupFill = null;
+					result.append(line).append("\n");
+				} else if (fill.equals(groupFill) && !group.isEmpty()
+						&& y == group.get(0)[3] && h == group.get(0)[1]
+						&& x == group.get(0)[2] + group.get(0)[0] * group.size()) {
+					group.add(new int[]{w, h, x, y});
+				} else {
+					flushRectGroup(result, group, groupFill);
+					group.clear();
+					groupFill = fill;
+					group.add(new int[]{w, h, x, y});
+				}
+			} else {
+				flushRectGroup(result, group, groupFill);
+				group.clear();
+				groupFill = null;
+				result.append(line).append("\n");
+			}
+		}
+		flushRectGroup(result, group, groupFill);
+		return result.toString();
+	}
+
+	private static void flushRectGroup(StringBuilder sb, ArrayList<int[]> group, String fill) {
+		if (group.isEmpty()) return;
+		int mergedWidth = group.get(0)[0] * group.size();
+		int[] first = group.get(0);
+		sb.append("<rect width=\"").append(mergedWidth).append("\" height=\"").append(first[1])
+		  .append("\" x=\"").append(first[2]).append("\" y=\"").append(first[3])
+		  .append("\" fill=\"").append(fill).append("\"/>\n");
+	}
+
 }