Print-on-demand formatting means interiors and covers built to a printer’s spec so a copy is made when someone orders it. KDP and Ingram-class plants reject (or print badly) files with wrong gutters, spines, or PDF versions.
POD formatting checklist
- Lock trim size before calculating spine width
- Margins and gutter that survive binding
- Embedded fonts and high-res images
- Print-ready PDF interior + wrap cover (front, spine, back, barcode area)
eBook files are a second job. Hub: book formatting services. Rails: IngramSpark vs KDP.