Background-image - Repeat X
And
Background-image - Repeat Y
Create a background image similar to the image below.
Use CSS to set the image as the background-image for your body. You will specify repeat-x to get it to tile horizontally (side to side). Make sure to match the body background-color to the bottom color of your image.
Also create another background image similar to the image linked below.
Click here for image
Use CSS to set the image as the background-image for your container div. You will specify repeat-y to get it to tile vertically (up and down). Make sure to use a transparent canvas color and export your image as a gif.