title: layer system in fabric.js canvas
body: <p>I am designing business card designer application with fabric.js canvas in this application i need a system for managing objects  z-index and for that i created two buttons for sending selected object in back and front its working fine but in all my designs i have a background image on which all text and objects placed when i send a object back it send back under that BG image how can stop that i mean i want that BG image to always in last position</p>
  
  <p><a href="https://i.stack.imgur.com/eVOGH.jpg" rel="nofollow noreferrer">preview of application</a></p>
  
  <p><strong>Code i am using now to send object in front and back</strong></p>
  
  <pre><code> var selectedObject;
        canvas.on('object:selected', function(event) {
          selectedObject = event.target;
        });
  
        var sendSelectedObjectBack = function() {
          canvas.sendToBack(selectedObject);
        }
  
        var sendSelectedObjectToFront = function() {
          canvas.bringToFront(selectedObject);
        }
  </code></pre>