     private var originalMaskFilters:Array;
     
     /**
-     *  The mask type.
-     *  Possible values are <code>MaskType.CLIP</code> and <code>MaskType.ALPHA</code> 
-	 *  or <code>MaskType.LUMINOSITY</code>. 
+     *  <p>The mask type. Possible values are <code>MaskType.CLIP</code>, <code>MaskType.ALPHA</code> 
+	 *  or <code>MaskType.LUMINOSITY</code>.</p> 
      *
-     *  <p>The default value is <code>MaskType.CLIP</code>, corresponding to "clip".</p>
+	 *  <p>Clip Masking</p>
+     * 
+     *  <p>When masking in clip mode, a clipping masks is reduced to 1-bit.  This means that a mask will 
+     *  not affect the opacity of a pixel in the source content; it either leaves the value unmodified, 
+     *  if the corresponding pixel in the mask is has a non-zero alpha value, or makes it fully 
+     *  transparent, if the mask pixel value has an alpha value of zero.</p>
+	 * 
+	 *  <p>Alpha Masking</p>
+     * 
+     *  <p>In alpha mode, the opacity of each pixel in the source content is multiplied by the opacity 
+     *  of the corresponding region of the mask.  i.e., a pixel in the source content with an opacity of 
+     *  1 that is masked by a region of opacity of .5 will have a resulting opacity of .5.  A source pixel 
+     *  with an opacity of .8 masked by a region with opacity of .5 will have a resulting opacity of .4.</p>
+	 * 
+	 *  <p>Luminosity Masking</p>
+     * 
+	 *  <p>A luminosity mask, sometimes called a 'soft mask', works very similarly to an alpha mask
+	 *  except that both the opacity and RGB color value of a pixel in the source content is multiplied
+	 *  by the opacity and RGB color value of the corresponding region in the mask.</p>
+	 * 
+	 *  <p>Luminosity masking is not native to Flash but is common in Adobe Creative Suite tools like Adobe 
+	 *  Illustrator and Adobe Photoshop. In order to accomplish the visual effect of a luminosity mask in 
+	 *  Flash-rendered content, a graphic element specifying a luminosity mask actually instantiates a shader
+	 *  filter that mimics the visual look of a luminosity mask as rendered in Adobe Creative Suite tools.</p>
+	 * 
+	 *  <p>Objects being masked by luminosity masks can set properties to control the RGB color value and 
+	 *  clipping of the mask. See the luminosityInvert and luminosityClip attributes.</p>
+	 * 
+     *  @default MaskType.CLIP 
      *
      *  @see  spark.core.MaskType
      *  

                _layout.updateScrollRect(unscaledWidth, unscaledHeight);
        }
    }
    
    /**
     *  @private

            return;

        _luminosityClip = value;
		luminositySettingsChanged = true;
		invalidateDisplayList();
    }
    
   /**
