The library laser printer that prints double-sided is no longer working properly. We have replaced it with the older laser printer so for now double-sided printing is unavailable. Since diagnosing the problem has been rather vexing there is no anticipated date when we expect to have double-sided printing available again.
If you absolutely need something printed double-sided, you will have to first print it out and then use the photocopy to make your double-sided copy. Photocopies cost 10 cents per page/side for black & white and 15 cents per page/side for color.