http://www.ecofont.com/en/products/green/font/download-the-ink-saving-font.html
This free, widely-used, enhancement to the fonts you already use, saves 28.1% in toner, by printing letters in a swiss-cheese manner, saving on the holes. The holes are invisible to the reader at 10-14 size fonts. The coverage of a printed document can be analyzed with software (Apfill). Print a page, for example with Arial and then print the same text with Ecofont Arial. Scan both documents at a high resolution (minimum of 300dpi) and analyze the coverage of both documents for savings evidence. The test result is a toner saving of 28.1% (tested for Arial and Ecofont Arial 12pts).
