kw: observations, typography, fonts, efficiency
I wrote a post last October in which I compared the "ink economy" of Ecofont with some standards, and a new extra-light font. Now printer.com has done an actual study using printers with different default typefaces and face sizes, as reported by CNet.
Their results shown here indicate that Century Gothic just outdoes Ecofont. However, the effective face width differs for different fonts.
For example, while a sample of Verdana may cover 4.55% of the paper, where the same text in Arial covers 4.97%, if the two are printed at the same face size, the Verdana sample will take up more total horizontal space than the Arial sample (I am assuming the baseline-to-baseline distance is set the same for the two faces). Thus, a large work such as a book chapter might require more pages in Verdana, at the same face size. A slightly smaller percentage of a larger number of pages might or might not actually save something.
It will take some fooling around to determine to what extent this latter factor might change the economic figures shown here. Don't hold your breath, but I expect that printing a book using 10pt Verdana will cost a bit more, using more pages and more ink, than printing it using Arial. Then again, I wouldn't print a book in a Sans Serif typeface, I'd use Times New Roman, which is more economical than Verdana or Arial, on both counts.