title: How to make a border in a SKScene using a custom image
body: <p>So I want to create a border around my SKScene so I created a png file that has a blue border with an opacity of 0.8 around the edges and is clear on the inside. I then added it to my SKScene after adding my background image. The border goes right on top of the background like I want but when I create new SKSpriteNodes their image goes over the border instead of underneath it. I tried setting the zPosition of the border but that just causes no new SKSpriteNodes to show up, even though the inside of the border is clear. What I want is to have new SKSpriteNode's to go under the border, they should still be visible a little because the border has an opacity of 0.8, and still be visible inside the border. Does anyone know what I'm doing wrong or how to do this right?</p>
  
  <p>Thanks!</p>