One of the problems with many browsers is that when they print a page from a web site, they add a header and footer to the page. These can be removed if required, but it is not a simple matter. A typical page with and without headers and footers is shown.
In many cases and especially when you are producing clean copies of web pages either for display or for use as such things as sales flyers, you need to print the pages without any headers and footers.
Note that all the pages in this Refreshing Browser web site have been designed to a width and height that makes printing easy without any reformatting.