When you print a page, you want just the workspace of the page in normal portrait view - not banner ads, left navigation bars or text that extends off the printed page . This is a printer-friendly view. There are at least two categories of solutions:
- Have a "click here for printer-friendly version" link that posts back to the server, does manipulation such as hiding menus, and creates a new instance of the page in printer-friendly mode
- Use Cascading Style Sheets (CSS).
The former has several problems that the latter solves:
- It posts back to the server, which hurts performance
- It becomes a nightmare if you want to open a new instance of the page for printing, such that closing this print-page won't accidentally close the main app page.
- It is a pain for editable pages because it requires the developer to manually persist all values to the new print page. Say the user enters a value in a text field, how do you persist that to a new page instance, perhaps via querystring or session? But what if the values are large?
- It requires additional effort for each page.
CSS provides a "media" attribute that can apply different style sheets to different media. The two media we're looking at here are screen (default) and print.
A stylesheet can set the color, visibility, or any other style that's relevant to a print-version. Here's a practical example that hides buttons (you can click a button in printview) and formats all text in greycolor (you many not want to waste color printing on text):
Eric Myer has a great article that explains how to use CSS for printing.