Could I save printer's ink/toner by changing the font?

University of Wisconsin Green Bay changed to Century Gothic, which they claim uses roughly 30 percent less ink when printed on paper. Here's an article on the University change.

Folks at Ecofont say theirs saves more. Looks like a bit of a debate but ongoing research might find a winner.

Here is an EcoFont comparison with other well known fonts.

Here are Arial and EcoFont compared:

I'd suggest using draft mode - its faster and uses less ink.

There's also a font with holes in it by a company called ecofont which you can download here based off bitstream vera

Two other fonts to check out - Secret Code for VERY thin stroke weight, and its still sans serif for most part. If you wanted to print small and legible, maybe Tiny - which is readable up to font size 4 (tho, not the best idea for a large amount of text) - both free fonts from squaregear/i shot the serif

At some point the cost of printing the document on an inkjet printer becomes more than the cost of purchasing an inexpensive laserjet. Depending on coverage (the percentage of the page covered with ink) the cost in ink to print a 200 page document can quickly approach $10-$15, and this is if you've optimized the fonts and are using whatever Eco-mode your printer supports.

At this price, printing the document ten times will cover the price of a new inexpensive HP laser printer. Printing black only on an inexpensive laser printer can result in up to a 10x price reduction. By my own figures, pages printed on my office laserjet printers cost less than 2/10 of a cent per page. While these are enterprise-class printers that have much lower cost per pages than consumer level laser printers, the economics are not too far off. Cost per page on my own HP Laserjet 1050 at home has been around half a cent compared with 2-3 cents per page inkjet.

While this in no way answers the specifics of your question, I believe that if you are planning on needing to print this document more than 5 times along with normal everyday printing in a home setting, you'll find a laser printer will be very much less expensive. Not to mention that laser printers, due to their fewer moving parts (no ink carriage running back and forth, just heaters and paper-moving rollers), tend to have longer lifes and lower total cost of ownership.