diff --git a/editions/prerelease/tiddlers/sidebarwidth.tid b/editions/prerelease/tiddlers/sidebarwidth.tid
new file mode 100644
index 000000000..8bb21a684
--- /dev/null
+++ b/editions/prerelease/tiddlers/sidebarwidth.tid
@@ -0,0 +1,2 @@
+title: $:/themes/tiddlywiki/vanilla/metrics/sidebarwidth
+text: 450px
diff --git a/editions/prerelease/tiddlers/theme.tid b/editions/prerelease/tiddlers/theme.tid
index 58690c397..3952c26b3 100644
--- a/editions/prerelease/tiddlers/theme.tid
+++ b/editions/prerelease/tiddlers/theme.tid
@@ -1,3 +1,3 @@
 title: $:/theme
 
-$:/themes/tiddlywiki/snowwhite
\ No newline at end of file
+$:/themes/tiddlywiki/heavier
\ No newline at end of file
diff --git a/editions/prerelease/tiddlywiki.info b/editions/prerelease/tiddlywiki.info
index 3fe2c2159..3e214694f 100644
--- a/editions/prerelease/tiddlywiki.info
+++ b/editions/prerelease/tiddlywiki.info
@@ -20,6 +20,7 @@
 		"tiddlywiki/starlight",
 		"tiddlywiki/seamless",
 		"tiddlywiki/centralised",
+		"tiddlywiki/heavier",
 		"tiddlywiki/tight",
 		"tiddlywiki/readonly"
 	],
diff --git a/editions/tw5.com/tiddlers/system/theme.tid b/editions/tw5.com/tiddlers/system/theme.tid
index 58690c397..3952c26b3 100644
--- a/editions/tw5.com/tiddlers/system/theme.tid
+++ b/editions/tw5.com/tiddlers/system/theme.tid
@@ -1,3 +1,3 @@
 title: $:/theme
 
-$:/themes/tiddlywiki/snowwhite
\ No newline at end of file
+$:/themes/tiddlywiki/heavier
\ No newline at end of file
diff --git a/editions/tw5.com/tiddlywiki.info b/editions/tw5.com/tiddlywiki.info
index 157f8ce80..faa54fc1d 100644
--- a/editions/tw5.com/tiddlywiki.info
+++ b/editions/tw5.com/tiddlywiki.info
@@ -14,6 +14,7 @@
 		"tiddlywiki/seamless",
 		"tiddlywiki/centralised",
 		"tiddlywiki/tight",
+		"tiddlywiki/heavier",
 		"tiddlywiki/readonly"
 	],
 	"languages": [
diff --git a/themes/tiddlywiki/heavier/base.tid b/themes/tiddlywiki/heavier/base.tid
new file mode 100644
index 000000000..b563fa255
--- /dev/null
+++ b/themes/tiddlywiki/heavier/base.tid
@@ -0,0 +1,68 @@
+title: $:/themes/tiddlywiki/heavier/base
+tags: [[$:/tags/Stylesheet]]
+
+\rules only filteredtranscludeinline transcludeinline macrodef macrocallinline
+
+html body h1,
+html body h2,
+html body h3,
+html body h4,
+html body h5,
+html body h6 {
+	font-weight: 600;
+}
+
+html body strong {
+	font-weight: 700;
+}
+
+html body .tc-tiddler-frame .tc-tiddler-body {
+	font-weight: 500;
+}
+
+html body button.tc-tiddlylink,
+html body a.tc-tiddlylink {
+	font-weight: 700;
+}
+
+html body a.tc-tiddlylink-shadow {
+	font-weight: 700;
+}
+
+html body a.tc-tiddlylink-shadow.tc-tiddlylink-resolves {
+	font-weight: 500;
+}
+
+html body button.tc-tag-label,
+html body span.tc-tag-label {
+	font-weight: 500;
+}
+
+html body .tc-sidebar-header .tc-title a.tc-tiddlylink-resolves {
+	font-weight: 500;
+}
+
+html body .tc-menu-list-count {
+	font-weight: 700;
+}
+
+html body .tc-view-field-name {
+	font-weight: 400;
+}
+
+html body .tc-site-title,
+html body .tc-titlebar {
+	font-weight: 500;
+}
+
+html body .tc-subtitle {
+	font-weight: 500;
+}
+
+html body .tc-tiddler-missing .tc-title {
+	font-weight: 500;
+}
+
+html body .tc-tab-buttons button {
+	font-weight: 500;
+}
diff --git a/themes/tiddlywiki/heavier/plugin.info b/themes/tiddlywiki/heavier/plugin.info
new file mode 100644
index 000000000..d05abbcd8
--- /dev/null
+++ b/themes/tiddlywiki/heavier/plugin.info
@@ -0,0 +1,9 @@
+{
+	"title": "$:/themes/tiddlywiki/heavier",
+	"name": "Heavier",
+	"author": "JeremyRuston",
+	"core-version": ">=5.0.0",
+	"plugin-type": "theme",
+	"description": "Heavier font theme",
+	"dependents": ["$:/themes/tiddlywiki/snowwhite"]
+}