The Page Order Math Behind Saddle-Stitch Booklets Is Weirder Than You Think. So I Automated It. [Devlog #8]

All tests run on an 8-year-old MacBook Air. Print pages 1, 2, 3, 4 in order, fold the paper — and the result is wrong. Booklet printing requires a completely different page ordering. For an 8-page booklet, you print [8, 1] on the front of sheet 1, [2, 7] on the back. This is called imposition, and it's a paid feature in InDesign and Acrobat. I built it in Rust. The math For a saddle-stitch booklet, total pages must be a multiple of 4 (blank pages pad the remainder). Each sheet carries 4 logical