CSS sprites Wiki says:
To reduce the number of requests the browser makes to the server, some web designerscombine numerous small images or icons into a larger image called a sprite sheet
You can read advantage of CSS sprites here. Example of CSS sprites can be found here.
Background: Now the catch we had was while using CSS sprite to create repeatable image effect. When we increased width using css we saw the adjacent image repeating.
Solution: We used a single image vertical css sprite: image source.
Complete solution in here.