“Creep” is the term used in the printing business when the inner papers of a saddle-stitched booklet extend (or creep) out further than the outer pages of the booklet when it’s folded. See the illustration below:
When laying out the pages for booklets, designers have to remember to account for creep. The more pages in a booklet and the thicker the paper, creep can become really noticeable and text can be lost when the booklet is trimmed at the print shop. The outside margins of each page must be adjusted as you get closer to the center. Printers also have to adjust for creep
magazine, they usually provide a template or precise instructions for bleed but the file still need to have bleed on all sides. The part where the fold or binding is will still be cut or folded. Printers also adjust the creep. Pages aren’t cut at the same exact width on thicker booklets, or pages in the middle will look wider than the pages closer to the covers. Printing companies use charts or software that help calculate the amount the layouts need to be moved toward the gutter (the inner margin) to keep margins even after they’re trimmed.
