adding a background image to a Drupal site I have a high-resolution white-paper texture background that I want to add to my Drupal site with the default Bartik theme.

I've looked at several posts across the web on how to do this with no clear answer.

I also haven't been able to find a Drupal module to do this. Most of the advice I've read is to modify the theme's CSS files.

But it's not clear which CSS file I should edit.  Colors.css, style.css?

I'm almost certain that the line I need to add is 


 background-image: url("/images/papertexture.jpg").



But I'm not sure where to add the CSS.
You can try the background image module


  This is an api module that provides tools to add background images to
  html elements using the css "background" property. A basic settings
  page is supplied as well as functions to easily add the "background"
  property to the page.