In printing terms, "creep" refers to the inner pages of a saddle-stitched booklet that stick out a bit more than the outer pages. This happens because the edges of the inner pages are narrower when the pages are folded and bound.
If you ignore it, page numbers and borders can shift towards the edges and throw off your layout.
Creep happens when the paper folds, thicker paper and more pages make it worse. The inner pages shift outwards more than the outer ones, so your margins can end up uneven.
If your booklet has under 40 pages, creep isn’t usually an issue. But for larger booklets, you’ll need to adjust the layout to keep margins consistent, especially near the spine. Always leave enough safe space to prevent text or graphics from creeping too close to the edge.
Tip: If you are looking to produce a high-page count booklet and are worried about the effects of creep, we suggest that you opt for a Perfect Bound Book. The way that this book is constructed reduces the risk of creep affecting your content.