Costum headers is when you have an image as a background in your tables. I've been using this several times, and I think it looks really cool!
1. Copy this code.
2. Paste it into whatever header you want to. I have chosen to custom my first header: H1. The image below will show you where you'll have to paste the code.
2. Now, pick out the image that you want to use as your costum header. Copy the URL of the image and paste it where it says IMAGE URL HERE!!!
