title: How to put a 1 px wide black border around the outer most edge of all layers in a Photoshop document?
body: <p>I'm separating an image into various layers in Photoshop to be used by After Effects.  The layers have different amounts of transparent pixels.  Apparently, transparent pixels can change the size of a layer and this confuses AE.  For example, scale by a percentage can differ for each layer.</p>
  <p>What solves the problem is to put black corners in all the layers.  What I thought would be simpler would be to put a 1 px wide black border around all the layers as defined by the original image.</p>
  <p>Can someone think of an easy way to do this?  I'm splitting an image into 5 to 10 layers and would like to be able to do this by selecting all the layers and say &quot;make a 1px wide border&quot;.</p>