People sometimes want to print web pages and the way the page has been styled doesn't always make for a good printable version. 

Using this block allows you to add custom styles on the page so when the vistor hits the printer friendly link a new window is opened and the styles you specify are applied only for the new window giving you clean version of your page that is printer friendly.

To use this effectively you need to know your page layout, html elements and css styles and be familar with CSS.

Brief how to video

http://youtu.be/cv4--3Lvrxo