Greening IT doesn't just mean greening the data center and PCs --- it also means greening printing as well. Doing that in a large business can save several million dollars a year. I recently interviewed two top "green" executives at HP, and got their six top tips for how to green your organization's printing.

I spoke with Maggie Davis, HP Environmental Marketing Manager for Worldwide Sales & Services within HP's Imaging and Printing Group, and Tom Codd, Director of Enterprise Marketing for Worldwide Sales & Services within the group. They provided a glimpse of HP's Green IT Action Plan for greening printing --- get the full plan here yourself.

I also asked them for their top six tips for greening printing in an organization. Here's what they told me.

Assess your imaging environment and use a carbon footprint calculator
Just how much energy are you wasting, and how much of a carbon footprint does your organization have when it comes to printing? One way to find out is to use HP's Carbon Footprint Calculator for printing. You may want to start small, for example, doing the calculation on a single department, such as the finance department. Once you do it, you'll have a baseline, as well as an  estimate about how much you can save.

Optimize your printing infrastructure
If you're like most organizations, you suffer from "printer creep" --- you have a mix of personal printers, network printers, standalone faxes, old device, and more. In short, you've got too many people with too many printers, doing too much printing. Get rid of unneeded printers, and standardize on only a few models, ideally multifunction, networked printers. In addition, get rid of old printers, because they tend to use far too much energy.

Automatically turn off printers to save energy
Why keep your printers running at night, when no one uses them? Automate their shutdown and startup. One way to do it: Use HP's Web Jetadmin software.

Print on both sides of the paper
This is about as simple a green idea as you can get. Do it and you'll halve your paper costs, cut down on your carbon footprint. To make it easier, make sure your printers use their duplex capabilities. One way to do that is to use HP's universal print driver.

The savings can be enormous. HP, for example, estimates that it is going to save 800 tons of paper a year, merely by making duplex printing its standard.

Recycle responsibly
Don't throw away ink cartridges -- recycle them. All of the major printer manufacturers have cartridge recycling programs, so use them. The same holds for hardware; recycle your old printers. Make sure you find a responsible recycler. Start off with your print manufacturer and get their advice or use their program.

Digitize paper-based processes
Here's a common scene in many offices: Someone prints a document, then scans it, and then faxes it. Whenever possible, look to eliminate paper. Multifunction devices, for example, can send a fax as an electronic attachment, which means that no printing will be done at all.