diff --git a/lib/models/source.dart b/lib/models/source.dart
index b55d28e..f62ad78 100644
--- a/lib/models/source.dart
+++ b/lib/models/source.dart
@@ -11,13 +11,28 @@ enum SourceLanguage {
 /// What a Source's articles are for; see GLOSSARY.md. Each kind has its own
 /// section in the app and its own time window.
 enum SourceKind {
-  news('News'),
-  learning('Learning'),
-  fun('Fun');
+  news('News', feedsBriefing: true),
+  learning('Learning', fixedWindow: Duration(days: 14)),
+  fun('Fun', fixedWindow: Duration(days: 3), pictureLed: true);
 
-  const SourceKind(this.label);
+  const SourceKind(
+    this.label, {
+    this.feedsBriefing = false,
+    this.fixedWindow,
+    this.pictureLed = false,
+  });
 
   final String label;
+
+  /// Only News sources feed the Briefing.
+  final bool feedsBriefing;
+
+  /// How far back articles reach; null where the user sets it (News).
+  final Duration? fixedWindow;
+
+  /// Comics and memes are the picture: the reader shows it whole in the body
+  /// rather than as a cropped banner.
+  final bool pictureLed;
 }
 
 /// A Source of any [kind]; see GLOSSARY.md.
diff --git a/lib/services/feed_service.dart b/lib/services/feed_service.dart
index 5dce82e..e3af97c 100644
--- a/lib/services/feed_service.dart
+++ b/lib/services/feed_service.dart
@@ -23,15 +23,15 @@ class FeedService {
 
   static const _timeout = Duration(seconds: 20);
 
-  /// Fetches all [sources] in parallel and drops articles older than the age
-  /// [maxAgeOf] gives for their Source. Failing feeds are reported in
+  /// Fetches all [sources] in parallel and drops articles older than the time
+  /// window [windowOf] gives for their Source. Failing feeds are reported in
   /// [FeedResult.errors] instead of failing the whole refresh.
   ///
   /// [corsProxy] is only used on web, where browsers block cross-origin feed
   /// requests. It is prepended to the feed URL, e.g. `https://proxy/?url=`.
   Future<FeedResult> fetchAll(
     List<Source> sources, {
-    required Duration Function(Source source) maxAgeOf,
+    required Duration Function(Source source) windowOf,
     String corsProxy = '',
   }) async {
     final errors = <String, String>{};
@@ -50,7 +50,7 @@ class FeedService {
       for (final (i, list) in results.indexed)
         for (final a in list)
           if ((a.published == null ||
-                  a.published!.isAfter(now.subtract(maxAgeOf(sources[i])))) &&
+                  a.published!.isAfter(now.subtract(windowOf(sources[i])))) &&
               seen.add(a.id))
             a,
     ];
diff --git a/lib/state/app_state.dart b/lib/state/app_state.dart
index 305888e..111597a 100644
--- a/lib/state/app_state.dart
+++ b/lib/state/app_state.dart
@@ -82,22 +82,27 @@ class AppState extends ChangeNotifier {
       (settings.hidePaid && paywall.isPaid(a)) ||
       (settings.hideSponsored && paywall.isSponsored(a));
 
+  /// Articles from Sources whose kind passes [test] that the paid/sponsored
+  /// filters show, or with [hidden], those they hide.
+  Iterable<Article> _articlesWhere(bool Function(SourceKind kind) test,
+          {bool hidden = false}) =>
+      articles.where((a) => test(a.source.kind) && _isHidden(a) == hidden);
+
   /// Articles from Sources of [kind] after the paid/sponsored filters. Today
-  /// and the Briefing use News, the Learn tab the other kinds.
-  List<Article> articlesOf(SourceKind kind) =>
-      articles.where((a) => a.source.kind == kind && !_isHidden(a)).toList();
+  /// uses News, the Learn tab the other kinds.
+  List<Article> articlesOf(SourceKind kind) => _articlesWhere((k) => k == kind).toList();
 
   /// Articles from Sources of [kind] that the paid/sponsored filters hide.
-  int hiddenCountOf(SourceKind kind) =>
-      articles.where((a) => a.source.kind == kind && _isHidden(a)).length;
+  int hiddenCountOf(SourceKind kind) => _articlesWhere((k) => k == kind, hidden: true).length;
+
+  /// What the Briefing is made from: the shown articles of the kinds that
+  /// feed it (News).
+  List<Article> get briefingArticles => _articlesWhere((k) => k.feedsBriefing).toList();
 
   /// How far back articles from Sources of [kind] reach. News follows the
   /// user's setting; the other kinds age slower.
-  Duration windowOf(SourceKind kind) => switch (kind) {
-        SourceKind.news => Duration(hours: settings.maxAgeHours),
-        SourceKind.learning => const Duration(days: 14),
-        SourceKind.fun => const Duration(days: 3),
-      };
+  Duration windowOf(SourceKind kind) =>
+      kind.fixedWindow ?? Duration(hours: settings.maxAgeHours);
 
   List<Source> get allSources => [..._curated, ...customSources];
 
@@ -119,7 +124,7 @@ class AppState extends ChangeNotifier {
     notifyListeners();
     final result = await _feeds.fetchAll(
       enabledSources,
-      maxAgeOf: (source) => windowOf(source.kind),
+      windowOf: (source) => windowOf(source.kind),
       corsProxy: settings.corsProxy,
     );
     articles = result.articles;
@@ -292,7 +297,7 @@ class AppState extends ChangeNotifier {
   Future<void> generateBriefing() async {
     final summarizer = _summarizer;
     if (summarizer == null || briefingLoading) return;
-    final articles = articlesOf(SourceKind.news);
+    final articles = briefingArticles;
     if (articles.isEmpty) {
       briefingError = 'No articles loaded yet. Pull to refresh the feed first.';
       notifyListeners();
diff --git a/lib/ui/article_screen.dart b/lib/ui/article_screen.dart
index 3bb2079..1dc5709 100644
--- a/lib/ui/article_screen.dart
+++ b/lib/ui/article_screen.dart
@@ -6,7 +6,6 @@ import 'package:flutter/material.dart';
 import 'package:flutter_inappwebview/flutter_inappwebview.dart';
 
 import '../models/article.dart';
-import '../models/source.dart';
 import '../services/article_extractor.dart';
 import '../services/consent_service.dart';
 import '../services/content_blocking.dart';
@@ -276,9 +275,7 @@ class _ReaderView extends StatelessWidget {
         builder: (context, snapshot) {
           final loaded = snapshot.data;
           var blocks = loaded?.blocks ?? const <ReaderBlock>[];
-          // Comics and memes are the picture: show it whole in the body
-          // rather than as a cropped banner.
-          final pictureLed = article.source.kind == SourceKind.fun;
+          final pictureLed = article.source.kind.pictureLed;
           final banner = pictureLed ? null : article.imageUrl;
           // The page's own hero image duplicates the feed image shown on top.
           if (banner != null) {
diff --git a/lib/ui/briefing_screen.dart b/lib/ui/briefing_screen.dart
index b8a69d6..32fa414 100644
--- a/lib/ui/briefing_screen.dart
+++ b/lib/ui/briefing_screen.dart
@@ -1,7 +1,6 @@
 import 'package:flutter/material.dart';
 
 import '../models/briefing.dart';
-import '../models/source.dart';
 import '../state/app_state.dart';
 import 'article_screen.dart';
 import 'briefing_history_screen.dart';
@@ -60,7 +59,7 @@ class BriefingScreen extends StatelessWidget {
     if (state.briefingLoading) {
       return EmptyState(
         icon: Icons.hourglass_top,
-        title: 'Reading ${state.articlesOf(SourceKind.news).length} headlines…',
+        title: 'Reading ${state.briefingArticles.length} headlines…',
         message: 'This usually takes 10-60 seconds.',
         action: const SizedBox(width: 160, child: LinearProgressIndicator()),
       );
@@ -70,7 +69,7 @@ class BriefingScreen extends StatelessWidget {
       icon: const Icon(Icons.auto_awesome),
       label: Text(state.loading
           ? 'Waiting for feeds…'
-          : 'Generate from ${state.articlesOf(SourceKind.news).length} articles'),
+          : 'Generate from ${state.briefingArticles.length} articles'),
     );
     if (briefing == null) {
       return EmptyState(
diff --git a/test/source_kinds_test.dart b/test/source_kinds_test.dart
index bb49562..352912a 100644
--- a/test/source_kinds_test.dart
+++ b/test/source_kinds_test.dart
@@ -1,10 +1,13 @@
 import 'dart:convert';
 
 import 'package:daily_tech_news/data/default_sources.dart';
+import 'package:daily_tech_news/models/app_settings.dart';
 import 'package:daily_tech_news/models/article.dart';
 import 'package:daily_tech_news/models/briefing.dart';
 import 'package:daily_tech_news/models/source.dart';
 import 'package:daily_tech_news/services/summarizer.dart';
+import 'package:daily_tech_news/ui/briefing_screen.dart';
+import 'package:flutter/material.dart';
 import 'package:flutter_test/flutter_test.dart';
 import 'package:shared_preferences/shared_preferences.dart';
 
@@ -62,6 +65,37 @@ void main() {
     expect(_titles(summarizer.briefingInput!), ['News from this morning']);
   });
 
+  test('the Briefing reads the shown News articles, not Learning, Fun or hidden ones', () async {
+    final xkcd = testSource('xkcd', SourceKind.fun);
+    final state = await launchApp([verge, bytebytego, xkcd], feeds: {
+      verge.feedUrl: [('News from this morning', const Duration(hours: 2)),
+        ('Sponsored: Buy our phone', const Duration(hours: 3))],
+      bytebytego.feedUrl: [('Explainer from today', const Duration(hours: 1))],
+      xkcd.feedUrl: [('Comic from today', const Duration(hours: 1))],
+    });
+
+    expect(_titles(state.briefingArticles), ['News from this morning']);
+  });
+
+  testWidgets('the Briefing tab counts only the articles the Briefing is made from',
+      (tester) async {
+    final state = (await tester.runAsync(() async {
+      final state = await launchApp([verge, bytebytego], feeds: {
+        verge.feedUrl: [('News from this morning', const Duration(hours: 2))],
+        bytebytego.feedUrl: [('Explainer from today', const Duration(hours: 1)),
+          ('Explainer from yesterday', const Duration(days: 1))],
+      });
+      await state.updateSettings(
+          state.settings.copyWith(aiProvider: AiProvider.claude, claudeApiKey: 'key'));
+      return state;
+    }))!;
+
+    await tester.pumpWidget(
+        MaterialApp(home: BriefingScreen(state: state, openSettings: () {})));
+
+    expect(find.text('Generate from 1 articles'), findsOneWidget);
+  });
+
   test('News follows the window setting', () async {
     SharedPreferences.setMockInitialValues({'max_age_hours': 48});
     final state = await launchApp([verge], feeds: {
diff --git a/test/source_selection_test.dart b/test/source_selection_test.dart
index 8578bd0..f2027e1 100644
--- a/test/source_selection_test.dart
+++ b/test/source_selection_test.dart
@@ -10,7 +10,7 @@ import 'package:shared_preferences/shared_preferences.dart';
 class _NoFeeds extends FeedService {
   @override
   Future<FeedResult> fetchAll(List<Source> sources,
-          {required Duration Function(Source source) maxAgeOf, String corsProxy = ''}) async =>
+          {required Duration Function(Source source) windowOf, String corsProxy = ''}) async =>
       const FeedResult([], {});
 }
 
diff --git a/test/support/fake_app.dart b/test/support/fake_app.dart
index 4b659f3..6fe0d65 100644
--- a/test/support/fake_app.dart
+++ b/test/support/fake_app.dart
@@ -19,9 +19,9 @@ class FakeFeeds extends FeedService {
 
   @override
   Future<FeedResult> fetchAll(List<Source> sources,
-      {required Duration Function(Source source) maxAgeOf, String corsProxy = ''}) {
+      {required Duration Function(Source source) windowOf, String corsProxy = ''}) {
     refreshes++;
-    return super.fetchAll(sources, maxAgeOf: maxAgeOf, corsProxy: corsProxy);
+    return super.fetchAll(sources, windowOf: windowOf, corsProxy: corsProxy);
   }
 
   @override