diff --git a/dart/lib/discovery/client.dart b/dart/lib/discovery/client.dart
index 72e0668..5fac314 100644
--- a/dart/lib/discovery/client.dart
+++ b/dart/lib/discovery/client.dart
@@ -9,7 +9,6 @@
 import 'package:v23discovery/discovery.dart' as v23discovery;
 
 import '../models/all.dart' as model;
-import '../utils/asset.dart' as assetutil;
 
 final Logger log = new Logger('discovery/client');
 
@@ -49,12 +48,13 @@
   Map<String, String> serviceAttrs = new Map();
   serviceAttrs['deckid'] = presentation.deck.key;
   serviceAttrs['name'] = presentation.deck.name;
+  serviceAttrs['thumbnailkey'] = presentation.deck.thumbnail.key;
   v23discovery.Service serviceInfo = new v23discovery.Service()
     ..instanceId = presentation.key
     ..interfaceName = presentationInterfaceName
     ..instanceName = presentation.key
     ..attrs = serviceAttrs
-    ..addrs = [presentation.syncgroupName];
+    ..addrs = [presentation.syncgroupName, presentation.thumbnailSyncgroupName];
 
   v23discovery.AdvertiserProxy advertiser =
       new v23discovery.AdvertiserProxy.unbound();
@@ -166,15 +166,13 @@
       return;
     }
 
-    // TODO(aghassemi): For now we use the default thumbnail. We need to find a way
-    // to fetch the actual thumbnail from the other side.
-    var thumbnail =
-        await assetutil.getRawBytes(assetutil.defaultThumbnailAssetKey);
-    model.Deck deck =
-        new model.Deck(s.attrs['deckid'], s.attrs['name'], thumbnail.toList());
+    model.Deck deck = new model.Deck(s.attrs['deckid'], s.attrs['name'],
+        new model.BlobRef(s.attrs['thumbnailkey']));
     var syncgroupName = s.addrs[0];
+    var thumbnailSyncgroupName = s.addrs[1];
     model.PresentationAdvertisement presentation =
-        new model.PresentationAdvertisement(key, deck, syncgroupName);
+        new model.PresentationAdvertisement(
+            key, deck, syncgroupName, thumbnailSyncgroupName);
 
     _onFoundEmitter.add(presentation);
   }
diff --git a/dart/lib/loaders/demo_loader.dart b/dart/lib/loaders/demo_loader.dart
index 781dc6a..4585668 100644
--- a/dart/lib/loaders/demo_loader.dart
+++ b/dart/lib/loaders/demo_loader.dart
@@ -7,6 +7,7 @@
 
 import '../models/all.dart' as model;
 import '../stores/store.dart';
+import '../stores/utils/key.dart' as keyutil;
 import '../utils/asset.dart' as assetutil;
 import '../utils/uuid.dart' as uuidutil;
 import 'loader.dart';
@@ -50,28 +51,36 @@
   static const int maxNumSlides = 20;
 
   Future<model.Deck> _getRandomDeck() async {
-    var thumbnail = await assetutil
-        .getRawBytes(thumbnails[_rand.nextInt(thumbnails.length)]);
     var firstWord = firstWords[_rand.nextInt(firstWords.length)];
     var secondWord = secondWords[_rand.nextInt(secondWords.length)];
-    return new model.Deck(
-        uuidutil.createUuid(), '$firstWord $secondWord', thumbnail);
+    var thumbnail = await assetutil
+        .getRawBytes(thumbnails[_rand.nextInt(thumbnails.length)]);
+
+    var deckId = uuidutil.createUuid();
+    var blobRef = new model.BlobRef(
+        keyutil.getDeckBlobKey(deckId, uuidutil.createUuid()));
+
+    await _store.actions.putBlob(blobRef.key, thumbnail);
+
+    return new model.Deck(deckId, '$firstWord $secondWord', blobRef);
   }
 
-  Stream<model.Slide> _getRandomSlides() async* {
+  Stream<model.Slide> _getRandomSlides(model.Deck deck) async* {
     var numSlides = _rand.nextInt(maxNumSlides);
     for (var i = 0; i < numSlides; i++) {
       var slideIndex = i % slides.length;
-      yield new model.Slide(
-          i,
-          await assetutil.getRawBytes(
-              'assets/images/sample_decks/vanadium/${slideIndex + 1}.jpg'));
+      var blobRef = new model.BlobRef(
+          keyutil.getDeckBlobKey(deck.key, uuidutil.createUuid()));
+      var image = await assetutil.getRawBytes(
+          'assets/images/sample_decks/vanadium/${slideIndex + 1}.jpg');
+      await _store.actions.putBlob(blobRef.key, image);
+      yield new model.Slide(i, blobRef);
     }
   }
 
   Future loadDeck() async {
     var deck = await _getRandomDeck();
-    List<model.Slide> slides = await _getRandomSlides().toList();
+    List<model.Slide> slides = await _getRandomSlides(deck).toList();
     await _store.actions.addDeck(deck);
     await _store.actions.setSlides(deck.key, slides);
   }
diff --git a/dart/lib/models/all.dart b/dart/lib/models/all.dart
index e2dbdbd..ff29f7f 100644
--- a/dart/lib/models/all.dart
+++ b/dart/lib/models/all.dart
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+export 'blobref.dart';
 export 'deck.dart';
 export 'presentation_advertisement.dart';
 export 'question.dart';
diff --git a/dart/lib/models/blobref.dart b/dart/lib/models/blobref.dart
new file mode 100644
index 0000000..bf89028
--- /dev/null
+++ b/dart/lib/models/blobref.dart
@@ -0,0 +1,44 @@
+// Copyright 2015 The Vanadium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+import 'dart:async';
+
+import '../stores/store.dart';
+
+// TODO(aghassemi): Replace with the true Blob type when supported in Dart.
+const int maxNumTries = 100;
+const Duration interval = const Duration(milliseconds: 100);
+
+class BlobRef {
+  String _key;
+  String get key => _key;
+
+  BlobRef(this._key);
+
+  Future<List<int>> getData() {
+    var store = new Store.singleton();
+    int numTries = 0;
+
+    getBlobFromStore() async {
+      return store.actions.getBlob(key);
+    }
+
+    getBlobWithRetries() async {
+      // Don't fail immediately if blob is not found in store, it might be still syncing.
+      try {
+        numTries++;
+        var data = await getBlobFromStore();
+        return data;
+      } catch (e) {
+        if (numTries <= maxNumTries) {
+          return new Future.delayed(interval, getBlobWithRetries);
+        } else {
+          throw new ArgumentError.value(key, 'Blob not found');
+        }
+      }
+    }
+
+    return getBlobWithRetries();
+  }
+}
diff --git a/dart/lib/models/deck.dart b/dart/lib/models/deck.dart
index 133dc04..861d186 100644
--- a/dart/lib/models/deck.dart
+++ b/dart/lib/models/deck.dart
@@ -4,6 +4,8 @@
 
 import 'dart:convert';
 
+import 'blobref.dart';
+
 // Deck represents a deck of slides.
 class Deck {
   String _key;
@@ -12,8 +14,8 @@
   String _name;
   String get name => _name;
 
-  List<int> _thumbnail;
-  List<int> get thumbnail => _thumbnail;
+  BlobRef _thumbnail;
+  BlobRef get thumbnail => _thumbnail;
 
   Deck(this._key, this._name, this._thumbnail) {}
 
@@ -21,14 +23,14 @@
     Map map = JSON.decode(json);
     _key = key;
     _name = map['name'];
-    _thumbnail = map['thumbnail'];
+    _thumbnail = new BlobRef(map['thumbnailkey']);
   }
 
   String toJson() {
     // NOTE(aghassemi): We never serialize the key with the object.
     Map map = new Map();
     map['name'] = name;
-    map['thumbnail'] = thumbnail;
+    map['thumbnailkey'] = thumbnail.key;
     return JSON.encode(map);
   }
 
diff --git a/dart/lib/models/presentation_advertisement.dart b/dart/lib/models/presentation_advertisement.dart
index 5e19c4e..925fc8a 100644
--- a/dart/lib/models/presentation_advertisement.dart
+++ b/dart/lib/models/presentation_advertisement.dart
@@ -16,5 +16,9 @@
   String _syncgroupName;
   String get syncgroupName => _syncgroupName;
 
-  PresentationAdvertisement(this._key, this._deck, this._syncgroupName) {}
+  String _thumbnailSyncgroupName;
+  String get thumbnailSyncgroupName => _thumbnailSyncgroupName;
+
+  PresentationAdvertisement(
+      this._key, this._deck, this._syncgroupName, this._thumbnailSyncgroupName);
 }
diff --git a/dart/lib/models/slide.dart b/dart/lib/models/slide.dart
index e93b03a..7694ddd 100644
--- a/dart/lib/models/slide.dart
+++ b/dart/lib/models/slide.dart
@@ -4,26 +4,28 @@
 
 import 'dart:convert';
 
+import 'blobref.dart';
+
 // Slide represents a slide within a deck.
 class Slide {
   int _num;
   int get num => _num;
 
-  List<int> _image;
-  List<int> get image => _image;
+  BlobRef _image;
+  BlobRef get image => _image;
 
   Slide(this._num, this._image) {}
 
   Slide.fromJson(String json) {
     Map map = JSON.decode(json);
     _num = map['num'];
-    _image = map['image'];
+    _image = new BlobRef(map['imagekey']);
   }
 
   String toJson() {
     Map map = new Map();
     map['num'] = _num;
-    map['image'] = image;
+    map['imagekey'] = image.key;
     return JSON.encode(map);
   }
 
diff --git a/dart/lib/stores/actions.dart b/dart/lib/stores/actions.dart
index 678d30a..faca6ab 100644
--- a/dart/lib/stores/actions.dart
+++ b/dart/lib/stores/actions.dart
@@ -51,4 +51,13 @@
 
   // Sets the driver of a presentation to the given user.
   Future setDriver(String deckId, model.User driver);
+
+  //////////////////////////////////////
+  // Blobs
+
+  // Stores the given blob bytes under the given key.
+  Future putBlob(String key, List<int> bytes);
+
+  // Gets the blob bytes for the given key.
+  Future<List<int>> getBlob(String key);
 }
diff --git a/dart/lib/stores/syncbase/actions.dart b/dart/lib/stores/syncbase/actions.dart
index 8513b06..c1cec97 100644
--- a/dart/lib/stores/syncbase/actions.dart
+++ b/dart/lib/stores/syncbase/actions.dart
@@ -88,16 +88,28 @@
       throw new ArgumentError.value(deckId, 'Deck no longer exists.');
     }
 
-    String uuid = uuidutil.createUuid();
-    String syncgroupName = _getPresentationSyncgroupName(_state.settings, uuid);
-
     model.Deck deck = _state._getOrCreateDeckState(deckId)._deck;
-    var presentation =
-        new model.PresentationAdvertisement(uuid, deck, syncgroupName);
+    String presentationId = uuidutil.createUuid();
+    String syncgroupName = _getSyncgroupName(_state.settings, presentationId);
+    String thumbnailSyncgroupName =
+        _getSyncgroupName(_state.settings, deck.thumbnail.key);
 
+    var presentation = new model.PresentationAdvertisement(
+        presentationId, deck, syncgroupName, thumbnailSyncgroupName);
+
+    // Syncgroup for deck and presentation data, including blobs.
     await sb.createSyncgroup(_state.settings.mounttable, syncgroupName, [
       sb.SyncbaseClient.syncgroupPrefix(decksTableName, deckId),
-      sb.SyncbaseClient.syncgroupPrefix(presentationsTableName, deckId)
+      sb.SyncbaseClient.syncgroupPrefix(presentationsTableName, deckId),
+      sb.SyncbaseClient.syncgroupPrefix(blobsTableName, deckId)
+    ]);
+
+    // TODO(aghassemi): Use a simple RPC instead of a syncgroup to get the thumbnail.
+    // See https://github.com/vanadium/syncslides/issues/17
+    // Syncgroup for deck thumbnail.
+    await sb.createSyncgroup(
+        _state.settings.mounttable, thumbnailSyncgroupName, [
+      sb.SyncbaseClient.syncgroupPrefix(blobsTableName, deck.thumbnail.key)
     ]);
 
     await discovery.advertise(presentation);
@@ -238,6 +250,19 @@
     }
     await _setPresentationDriver(deckId, deckState.presentation.key, driver);
   }
+
+  //////////////////////////////////////
+  // Blobs
+
+  Future putBlob(String key, List<int> bytes) async {
+    sb.SyncbaseTable tb = await _getBlobsTable();
+    await tb.put(key, bytes);
+  }
+
+  Future<List<int>> getBlob(String key) async {
+    sb.SyncbaseTable tb = await _getBlobsTable();
+    return tb.get(key);
+  }
 }
 
 //////////////////////////////////////
@@ -250,9 +275,8 @@
       UTF8.encode(driver.toJson()));
 }
 
-String _getPresentationSyncgroupName(
-    model.Settings settings, String presentationId) {
-  return '${settings.mounttable}/${settings.deviceId}/%%sync/$presentationId';
+String _getSyncgroupName(model.Settings settings, String uuid) {
+  return '${settings.mounttable}/${settings.deviceId}/%%sync/$uuid';
 }
 
 Future<sb.SyncbaseTable> _getTable(String tableName) async {
@@ -275,3 +299,7 @@
 Future<sb.SyncbaseTable> _getPresentationsTable() {
   return _getTable(presentationsTableName);
 }
+
+Future<sb.SyncbaseTable> _getBlobsTable() {
+  return _getTable(blobsTableName);
+}
diff --git a/dart/lib/stores/syncbase/consts.dart b/dart/lib/stores/syncbase/consts.dart
index 0e4955a..0c93249 100644
--- a/dart/lib/stores/syncbase/consts.dart
+++ b/dart/lib/stores/syncbase/consts.dart
@@ -6,4 +6,5 @@
 
 const String decksTableName = 'decks';
 const String presentationsTableName = 'presentations';
+const String blobsTableName = 'blobs';
 final Logger log = new Logger('store/syncbase_store');
diff --git a/dart/lib/stores/syncbase/store.dart b/dart/lib/stores/syncbase/store.dart
index 252f6d7..3c8913f 100644
--- a/dart/lib/stores/syncbase/store.dart
+++ b/dart/lib/stores/syncbase/store.dart
@@ -81,6 +81,12 @@
     discovery.onFound.listen((model.PresentationAdvertisement newP) {
       _state._presentationsAdvertisements[newP.key] = newP;
       _triggerStateChange();
+
+      // TODO(aghassemi): Use a simple RPC instead of a syncgroup to get the thumbnail.
+      // See https://github.com/vanadium/syncslides/issues/17
+      // Join the thumbnail syncgroup to get the thumbnail blob.
+      String sgName = newP.thumbnailSyncgroupName;
+      sb.joinSyncgroup(sgName);
     });
 
     discovery.onLost.listen((String presentationId) {
@@ -242,5 +248,6 @@
   Future _ensureTablesExist() async {
     await _getDecksTable();
     await _getPresentationsTable();
+    await _getBlobsTable();
   }
 }
diff --git a/dart/lib/stores/utils/key.dart b/dart/lib/stores/utils/key.dart
index 83b8e1a..367dee9 100644
--- a/dart/lib/stores/utils/key.dart
+++ b/dart/lib/stores/utils/key.dart
@@ -141,3 +141,8 @@
 bool isPresentationQuestionKey(String key) {
   return _presentationQuestionPattern.hasMatch(key);
 }
+
+// Constructs a blob key specific to a deck.
+String getDeckBlobKey(String deckId, String blobId) {
+  return '$deckId/$blobId';
+}
diff --git a/dart/lib/utils/image_provider.dart b/dart/lib/utils/image_provider.dart
index d4029c1..78490a5 100644
--- a/dart/lib/utils/image_provider.dart
+++ b/dart/lib/utils/image_provider.dart
@@ -7,14 +7,23 @@
 import 'dart:ui' as ui;
 
 import 'package:flutter/services.dart';
+import 'package:logging/logging.dart';
 
 import '../models/all.dart' as model;
+import '../utils/asset.dart' as assetutil;
+
+final Logger log = new Logger('utils/image_provider');
+
+final ImageProvider defaultImageProvider = new _RawImageProvider(
+    'default_image',
+    () => assetutil.getRawBytes(assetutil.defaultThumbnailAssetKey));
 
 ImageProvider getDeckThumbnailImage(model.Deck deck) {
   if (deck == null) {
     throw new ArgumentError.notNull('deck');
   }
-  return new _RawImageProvider('thumbnail_${deck.key}', deck.thumbnail);
+
+  return new _RawImageProvider('thumbnail_${deck.key}', deck.thumbnail.getData);
 }
 
 ImageProvider getSlideImage(String deckId, model.Slide slide) {
@@ -24,15 +33,29 @@
   if (slide == null) {
     throw new ArgumentError.notNull('slide');
   }
-  return new _RawImageProvider('slide_${deckId}_${slide.num}', slide.image);
+
+  return new _RawImageProvider(
+      'slide_${deckId}_${slide.num}', slide.image.getData);
 }
 
+typedef Future<List<int>> BlobFetcher();
+
 class _RawImageProvider implements ImageProvider {
   final String imageKey;
-  final List<int> imageData;
+  final BlobFetcher blobFetcher;
 
-  _RawImageProvider(this.imageKey, this.imageData);
+  _RawImageProvider(this.imageKey, this.blobFetcher);
+
   Future<ui.Image> loadImage() async {
+    List<int> imageData;
+    try {
+      imageData = await blobFetcher();
+    } catch (e) {
+      log.warning('Blob for ${imageKey} not found.');
+      imageData =
+          await assetutil.getRawBytes(assetutil.defaultThumbnailAssetKey);
+    }
+
     return await decodeImageFromList(new Uint8List.fromList(imageData));
   }