diff --git a/CHANGELOG.md b/CHANGELOG.md
index aee4564e..a85ada36 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -8,6 +8,7 @@ you spot any mistakes.
 
 * BC break: `Graph::createVertices()` now returns an array of vertices instead of the chainable `Graph` (#19)
 * Feature: `Graph::createVertices()` now also accepts an array of vertex IDs (#19)
+* Fix: Various issues with `Vertex`/`Edge` layout attributes (#32)
 
 ## 0.5.0 (2013-05-07)
 
diff --git a/lib/Fhaculty/Graph/GraphViz.php b/lib/Fhaculty/Graph/GraphViz.php
index 3f1f5cc4..cedb8a25 100644
--- a/lib/Fhaculty/Graph/GraphViz.php
+++ b/lib/Fhaculty/Graph/GraphViz.php
@@ -5,6 +5,7 @@
 use Fhaculty\Graph\Algorithm\Groups;
 use Fhaculty\Graph\Exception\UnexpectedValueException;
 use Fhaculty\Graph\Exception\InvalidArgumentException;
+use Fhaculty\Graph\Edge\Base as Edge;
 use \stdClass;
 
 class GraphViz
@@ -34,6 +35,14 @@ class GraphViz
      */
     private $executable = 'dot';
 
+    /**
+     * string to use as indentation for dot output
+     *
+     * @var string
+     * @see GraphViz::createScript()
+     */
+    private $formatIndent = '  ';
+
     const DELAY_OPEN = 2.0;
 
     const EOL = PHP_EOL;
@@ -273,13 +282,13 @@ public function createScript()
         // add global attributes
         $layout = $this->graph->getLayout();
         if ($layout) {
-            $script .= '  graph ' . $this->escapeAttributes($layout) . self::EOL;
+            $script .= $this->formatIndent . 'graph ' . $this->escapeAttributes($layout) . self::EOL;
         }
         if ($this->layoutVertex) {
-            $script .= '  node ' . $this->escapeAttributes($this->layoutVertex) . self::EOL;
+            $script .= $this->formatIndent . 'node ' . $this->escapeAttributes($this->layoutVertex) . self::EOL;
         }
         if ($this->layoutEdge) {
-            $script .= '  edge ' . $this->escapeAttributes($this->layoutEdge) . self::EOL;
+            $script .= $this->formatIndent . 'edge ' . $this->escapeAttributes($this->layoutEdge) . self::EOL;
         }
 
         $alg = new Groups($this->graph);
@@ -288,25 +297,15 @@ public function createScript()
 
         if ($showGroups) {
             $gid = 0;
+            $indent = str_repeat($this->formatIndent, 2);
             // put each group of vertices in a separate subgraph cluster
             foreach ($alg->getGroups() as $group) {
-                $script .= '  subgraph cluster_' . $gid++ . ' {' . self::EOL .
-                           '    label = ' . $this->escape($group) . self::EOL;
+                $script .= $this->formatIndent . 'subgraph cluster_' . $gid++ . ' {' . self::EOL .
+                           $indent . 'label = ' . $this->escape($group) . self::EOL;
                 foreach($alg->getVerticesGroup($group) as $vid => $vertex) {
-                    $layout = $vertex->getLayout();
-
-                    $balance = $vertex->getBalance();
-                    if($balance !== NULL){
-                        if($balance > 0){
-                            $balance = '+' . $balance;
-                        }
-                        if(!isset($layout['label'])){
-                            $layout['label'] = $vid;
-                        }
-                        $layout['label'] .= ' (' . $balance . ')';
-                    }
+                    $layout = $this->getLayoutVertex($vertex);
 
-                    $script .= '    ' . $this->escapeId($vid);
+                    $script .= $indent . $this->escapeId($vid);
                     if($layout){
                         $script .= ' ' . $this->escapeAttributes($layout);
                     }
@@ -318,21 +317,10 @@ public function createScript()
             // explicitly add all isolated vertices (vertices with no edges) and vertices with special layout set
             // other vertices wil be added automatically due to below edge definitions
             foreach ($this->graph->getVertices() as $vid => $vertex){
-                $layout = $vertex->getLayout();
-
-                $balance = $vertex->getBalance();
-                if($balance !== NULL){
-                    if($balance > 0){
-                        $balance = '+' . $balance;
-                    }
-                    if(!isset($layout['label'])){
-                        $layout['label'] = $vid;
-                    }
-                    $layout['label'] .= ' (' . $balance . ')';
-                }
+                $layout = $this->getLayoutVertex($vertex);
 
                 if($vertex->isIsolated() || $layout){
-                    $script .= '  ' . $this->escapeId($vid);
+                    $script .= $this->formatIndent . $this->escapeId($vid);
                     if($layout){
                         $script .= ' ' . $this->escapeAttributes($layout);
                     }
@@ -349,43 +337,16 @@ public function createScript()
             $currentStartVertex = $both[0];
             $currentTargetVertex = $both[1];
 
-            $script .= '  ' . $this->escapeId($currentStartVertex->getId()) . $edgeop . $this->escapeId($currentTargetVertex->getId());
-
-            $attrs = $currentEdge->getLayout();
+            $script .= $this->formatIndent . $this->escapeId($currentStartVertex->getId()) . $edgeop . $this->escapeId($currentTargetVertex->getId());
 
-            // use flow/capacity/weight as edge label
-            $label = NULL;
+            $layout = $this->getLayoutEdge($currentEdge);
 
-            $flow = $currentEdge->getFlow();
-            $capacity = $currentEdge->getCapacity();
-            // flow is set
-            if ($flow !== NULL) {
-                // NULL capacity = infinite capacity
-                $label = $flow . '/' . ($capacity === NULL ? '∞' : $capacity);
-            // capacity set, but not flow (assume zero flow)
-            } elseif ($capacity !== NULL) {
-                $label = '0/' . $capacity;
-            }
-
-            $weight = $currentEdge->getWeight();
-            // weight is set
-            if ($weight !== NULL) {
-                if ($label === NULL) {
-                    $label = $weight;
-                } else {
-                    $label .= '/' . $weight;
-                }
-            }
-
-            if ($label !== NULL) {
-                $attrs['label'] = $label;
-            }
             // this edge also points to the opposite direction => this is actually an undirected edge
             if ($directed && $currentEdge->isConnection($currentTargetVertex, $currentStartVertex)) {
-                $attrs['dir'] = 'none';
+                $layout['dir'] = 'none';
             }
-            if ($attrs) {
-                $script .= ' ' . $this->escapeAttributes($attrs);
+            if ($layout) {
+                $script .= ' ' . $this->escapeAttributes($layout);
             }
 
             $script .= self::EOL;
@@ -457,4 +418,60 @@ public static function raw($string)
     {
         return (object) array('string' => $string);
     }
+
+    protected function getLayoutVertex(Vertex $vertex)
+    {
+        $layout = $vertex->getLayout();
+
+        $balance = $vertex->getBalance();
+        if($balance !== NULL){
+            if($balance > 0){
+                $balance = '+' . $balance;
+            }
+            if(!isset($layout['label'])){
+                $layout['label'] = $vertex->getId();
+            }
+            $layout['label'] .= ' (' . $balance . ')';
+        }
+
+        return $layout;
+    }
+
+    protected function getLayoutEdge(Edge $edge)
+    {
+        $layout = $edge->getLayout();
+
+        // use flow/capacity/weight as edge label
+        $label = NULL;
+
+        $flow = $edge->getFlow();
+        $capacity = $edge->getCapacity();
+        // flow is set
+        if ($flow !== NULL) {
+            // NULL capacity = infinite capacity
+            $label = $flow . '/' . ($capacity === NULL ? '∞' : $capacity);
+            // capacity set, but not flow (assume zero flow)
+        } elseif ($capacity !== NULL) {
+            $label = '0/' . $capacity;
+        }
+
+        $weight = $edge->getWeight();
+        // weight is set
+        if ($weight !== NULL) {
+            if ($label === NULL) {
+                $label = $weight;
+            } else {
+                $label .= '/' . $weight;
+            }
+        }
+
+        if ($label !== NULL) {
+            if (isset($layout['label'])) {
+                $layout['label'] .= ' ' . $label;
+            } else {
+                $layout['label'] = $label;
+            }
+        }
+        return $layout;
+    }
 }
diff --git a/tests/Fhaculty/Graph/GraphVizTest.php b/tests/Fhaculty/Graph/GraphVizTest.php
new file mode 100644
index 00000000..181f6241
--- /dev/null
+++ b/tests/Fhaculty/Graph/GraphVizTest.php
@@ -0,0 +1,200 @@
+<?php
+
+use Fhaculty\Graph\Exception\RuntimeException;
+use Fhaculty\Graph\Exporter\Image;
+use Fhaculty\Graph\Vertex;
+use Fhaculty\Graph\Exception\OverflowException;
+use Fhaculty\Graph\Exception\InvalidArgumentException;
+use Fhaculty\Graph\Graph;
+use Fhaculty\Graph\GraphViz;
+
+class GraphVizTest extends TestCase
+{
+    public function testGraphEmpty()
+    {
+        $graph = new Graph();
+
+        $expected = <<<VIZ
+graph G {
+}
+
+VIZ;
+
+        $this->assertEquals($expected, $this->getDotScriptForGraph($graph));
+    }
+
+    public function testGraphIsolatedVertices()
+    {
+        $graph = new Graph();
+        $graph->createVertex('a');
+        $graph->createVertex('b');
+
+        $expected = <<<VIZ
+graph G {
+  "a"
+  "b"
+}
+
+VIZ;
+
+        $this->assertEquals($expected, $this->getDotScriptForGraph($graph));
+    }
+
+    public function testEscaping()
+    {
+        $graph = new Graph();
+        $graph->createVertex('a');
+        $graph->createVertex('b¹²³ is; ok\\ay, "right"?');
+        $graph->createVertex(3);
+        $graph->createVertex(4)->setLayoutAttribute('label', 'normal');
+        $graph->createVertex(5)->setLayoutAttribute('label', GraphViz::raw('<raw>'));
+
+
+        $expected = <<<VIZ
+graph G {
+  "a"
+  "b¹²³ is; ok\\\\ay, &quot;right&quot;?"
+  3
+  4 [label="normal"]
+  5 [label=<raw>]
+}
+
+VIZ;
+
+        $this->assertEquals($expected, $this->getDotScriptForGraph($graph));
+    }
+
+    public function testGraphDirected()
+    {
+        $graph = new Graph();
+        $graph->createVertex('a')->createEdgeTo($graph->createVertex('b'));
+
+        $expected = <<<VIZ
+digraph G {
+  "a" -> "b"
+}
+
+VIZ;
+
+        $this->assertEquals($expected, $this->getDotScriptForGraph($graph));
+    }
+
+    public function testGraphMixed()
+    {
+        // a -> b -- c
+        $graph = new Graph();
+        $graph->createVertex('a')->createEdgeTo($graph->createVertex('b'));
+        $graph->createVertex('c')->createEdge($graph->getVertex('b'));
+
+        $expected = <<<VIZ
+digraph G {
+  "a" -> "b"
+  "c" -> "b" [dir="none"]
+}
+
+VIZ;
+
+        $this->assertEquals($expected, $this->getDotScriptForGraph($graph));
+    }
+
+
+    public function testGraphUndirectedWithIsolatedVerticesFirst()
+    {
+        // a -- b -- c   d
+        $graph = new Graph();
+        $graph->createVertices(array('a', 'b', 'c', 'd'));
+        $graph->getVertex('a')->createEdge($graph->getVertex('b'));
+        $graph->getVertex('b')->createEdge($graph->getVertex('c'));
+
+        $expected = <<<VIZ
+graph G {
+  "d"
+  "a" -- "b"
+  "b" -- "c"
+}
+
+VIZ;
+
+        $this->assertEquals($expected, $this->getDotScriptForGraph($graph));
+    }
+
+    public function testVertexLabels()
+    {
+        $graph = new Graph();
+        $graph->createVertex('a')->setBalance(1);
+        $graph->createVertex('b')->setBalance(0);
+        $graph->createVertex('c')->setBalance(-1);
+        $graph->createVertex('d')->setLayoutAttribute('label', 'test');
+        $graph->createVertex('e')->setLayoutAttribute('label', 'unnamed')->setBalance(2);
+
+        $expected = <<<VIZ
+graph G {
+  "a" [label="a (+1)"]
+  "b" [label="b (0)"]
+  "c" [label="c (-1)"]
+  "d" [label="test"]
+  "e" [label="unnamed (+2)"]
+}
+
+VIZ;
+
+        $this->assertEquals($expected, $this->getDotScriptForGraph($graph));
+    }
+
+    public function testEdgeLayoutAtributes()
+    {
+        $graph = new Graph();
+        $graph->createVertex('1a')->createEdge($graph->createVertex('1b'));
+        $graph->createVertex('2a')->createEdge($graph->createVertex('2b'))->setLayoutAttribute('numeric', 20);
+        $graph->createVertex('3a')->createEdge($graph->createVertex('3b'))->setLayoutAttribute('textual', "forty");
+        $graph->createVertex('4a')->createEdge($graph->createVertex('4b'))->setLayoutAttribute(1, 1)->setLayoutAttribute(2, 2);
+        $graph->createVertex('5a')->createEdge($graph->createVertex('5b'))->setLayout(array('a' => 'b', 'c' => 'd'));
+
+        $expected = <<<VIZ
+graph G {
+  "1a" -- "1b"
+  "2a" -- "2b" [numeric=20]
+  "3a" -- "3b" [textual="forty"]
+  "4a" -- "4b" [1=1 2=2]
+  "5a" -- "5b" [a="b" c="d"]
+}
+
+VIZ;
+
+        $this->assertEquals($expected, $this->getDotScriptForGraph($graph));
+    }
+
+    public function testEdgeLabels()
+    {
+        $graph = new Graph();
+        $graph->createVertex('1a')->createEdge($graph->createVertex('1b'));
+        $graph->createVertex('2a')->createEdge($graph->createVertex('2b'))->setWeight(20);
+        $graph->createVertex('3a')->createEdge($graph->createVertex('3b'))->setCapacity(30);
+        $graph->createVertex('4a')->createEdge($graph->createVertex('4b'))->setFlow(40);
+        $graph->createVertex('5a')->createEdge($graph->createVertex('5b'))->setFlow(50)->setCapacity(60);
+        $graph->createVertex('6a')->createEdge($graph->createVertex('6b'))->setFlow(60)->setCapacity(70)->setWeight(80);
+        $graph->createVertex('7a')->createEdge($graph->createVertex('7b'))->setLayoutAttribute('label', 'prefixed')->setFlow(70);
+
+        $expected = <<<VIZ
+graph G {
+  "1a" -- "1b"
+  "2a" -- "2b" [label=20]
+  "3a" -- "3b" [label="0/30"]
+  "4a" -- "4b" [label="40/∞"]
+  "5a" -- "5b" [label="50/60"]
+  "6a" -- "6b" [label="60/70/80"]
+  "7a" -- "7b" [label="prefixed 70/∞"]
+}
+
+VIZ;
+
+        $this->assertEquals($expected, $this->getDotScriptForGraph($graph));
+    }
+
+
+    private function getDotScriptForGraph(Graph $graph)
+    {
+        $graphviz = new GraphViz($graph);
+        return $graphviz->createScript();
+    }
+}