To reduce consumption of papers, I investigated way to print both sides of paper on MacOSX.

1. First, print even number pages by reverse order.
2. Second, bring the output papers to the medium tray.
3. Last, print odd number pages.

Be careful of the flow of from even number pages to odd number pages. If you do oppositely, sometimes you would get the out of order result.

This can be used with layouts that have 2 or more pages a paper.