diff --git a/src/model.js b/src/model.js
index 79ac4aa8..cb102004 100644
--- a/src/model.js
+++ b/src/model.js
@@ -186,6 +186,20 @@ my.Field = Backbone.Model.extend({
       this.renderer = options.renderer;
       this.deriver = options.deriver;
     }
+    if (!this.renderer) {
+      this.renderer = this.defaultRenderers[this.get('type')];
+    }
+  },
+  defaultRenderers: {
+    object: function(val, field, doc) {
+      return JSON.stringify(val)
+    },
+    'float': function(val, field, doc) {
+      var format = field.get('format'); 
+      if (format === 'percentage') {
+        return val + '%';
+      }
+    }
   }
 });
 
@@ -217,7 +231,7 @@ my.FieldList = Backbone.Collection.extend({
 //  * query: Query in ES Query DSL <http://www.elasticsearch.org/guide/reference/api/search/query.html>
 //  * filter: See filters and <a href="http://www.elasticsearch.org/guide/reference/query-dsl/filtered-query.html">Filtered Query</a>
 //  * fields: set of fields to return - http://www.elasticsearch.org/guide/reference/api/search/fields.html
-//  * facets: TODO - see http://www.elasticsearch.org/guide/reference/api/search/facets/
+//  * facets: specification of facets - see http://www.elasticsearch.org/guide/reference/api/search/facets/
 // 
 // Additions:
 // 
diff --git a/test/model.test.js b/test/model.test.js
index 406692bc..2625a7a4 100644
--- a/test/model.test.js
+++ b/test/model.test.js
@@ -38,7 +38,20 @@ test('Field: basics', function () {
   equal('XX', out[0].label);
 });
 
-test('Field: deriver and renderer', function () {
+test('Field: default renderers', function () {
+  var doc = new recline.Model.Document({x: 12.3, myobject: {a: 1, b: 2}});
+  var field = new recline.Model.Field({id: 'myobject', type: 'object'});
+  var out = doc.getFieldValue(field);
+  var exp = '{"a":1,"b":2}';
+  equal(out, exp);
+
+  var field = new recline.Model.Field({id: 'x', type: 'float', format: 'percentage'});
+  var out = doc.getFieldValue(field);
+  var exp = '12.3%';
+  equal(out, exp);
+});
+
+test('Field: custom deriver and renderer', function () {
   var doc = new recline.Model.Document({x: 123});
   var cellRenderer = function(value, field) {
     return '<span class="field-' + field.id + '">' + value + '</span>';