Home Tools Imposition, spines and duplex fixes — the arithmetic and file surgery of making a book, free, running entirely in your browser. Your manuscript never leaves your machine: that is not a slogan, it is how these are built.
Booklet imposer Saddle-stitch imposition: print duplex, fold the stack, staple once. In your browser. 2-up imposer Cut-stack imposition: two pages a side, one cut, left pile on right pile. Spine calculator Page count and paper to millimetres of spine — plus the full flat cover width. Blank-page inserter Fix recto starts and odd totals by adding the blanks into the file itself. Page reverser For printers that output face-up and hand you the book back-to-front. Signature planner Pages to signatures — counts, ranges and blanks, in sewing order. Case calculator The hand-bound hardcover's full cut list: boards, spine, hinges, cloth. Yardage calculator Cloth cuts to roll metres — books per metre, metres per run. Weight calculator Pages and paper to grams — block, covers, boards itemised. Paper converter gsm ⇄ pounds across all five US basis weights — exactly. Spine text fit Title to spine width — the largest honest point size. Words → pages Word count to book pages — then sheets, spine and weight. Cover builder Front, spine, back images to a flat wraparound at true millimetres. De-imposer Booklet PDFs back to reading order — the exact inverse of the imposer. Spread splitter One guillotine stroke through every page — spreads become singles. Signature splitter One zipped file per signature, named in sewing order. Scan rebuilder Fronts + reversed backs interleaved — the book-scan fix. Folio stamper Page numbers in book convention — outer corners, honest skips. Crop marks & bleed Trim marks and 3 mm bleed, drawn where the blade expects them. Zine imposer Eight pages, one sheet, two folds, one cut, zero staples. Margin inspector Pages rendered with trim and safe-area guides over them. Chat statistics Who writes more, when it wakes, what it says in emoji. These are the tools — see everything we’ve written , or what a book costs .