Puzzle book interior PDF checklist for KDP

File and page setup

1. Page size. Every page is the trim size, for example 6 x 9 in. With bleed, every page is 0.125 in wider and 0.25 in taller. Pages of mixed sizes do not match the trim and get flagged.
2. Single pages. Upload pages one after another, not side-by-side spreads.
3. Page count. At least 24 pages, and within the maximum for your trim and paper. An odd count is rounded up to the next even number by KDP.
4. No extras. No crop marks, comments, annotations, bookmarks or form fields. Export a plain print PDF.

Margins and content

1. Inside margin at least the KDP minimum for the final page count: 0.375 in up to 150 pages, 0.5 in up to 300, and so on. See the margins guide.
2. Outside, top and bottom at least 0.25 in (0.375 in with bleed). Page numbers count.
3. Nothing cut off. Grids, word lists and clue numbers all fully inside the margins on left and right pages.

Fonts, lines and images

1. Fonts embedded. In your PDF viewer's document properties, every font should say Embedded or Embedded Subset.
2. Nothing smaller than 7 pt. That includes the small numbers in Killer Sudoku cages and the clue numbers of Nonograms and Kakuro.
3. Lines at least 0.75 pt. Thin inner grid lines are the usual problem. Very thin lines may print faint or broken.
4. Images at 300 DPI or more, if you use any.

Puzzle content

1. Every puzzle has exactly one solution. A puzzle with two solutions makes the answer key "wrong" for some readers. See answer keys and unique solutions.
2. Answer key matches. Puzzle 37 in the book is solution 37 in the key, with the same type and level labels.
3. How-to pages for every puzzle type in the book, especially for less known ones like Slitherlink or Masyu.

After upload

Open KDP's print previewer and go through every page, not only the flagged ones. It shows the trim line and margins and lists problems it found. Order a proof copy before the first book in a new format; a printed grid tells you more about cell size and line weight than any screen.

Also check that what you tick in the details matches the book: puzzle books are not low-content books by KDP's definition, and AI-generated content must be disclosed. See are puzzle books low content? and AI disclosure.

What Gridbinder checks for you

The studio takes care of most of this list: the page is the trim size with no bleed, pages are single, a short book gets lined notes pages to reach 24, the PDF has no bookmarks or comments, margins come from the final page count with an eighth of an inch to spare, the fonts are embedded in full, text is 7 pt or larger, every puzzle is proved to have exactly one solution, and the answer key and how-to pages are made with the puzzles. Two checks stay with you. Line weight: in our own check in October 2026, some thin inner grid lines in Gridbinder books were 0.6 to 0.7 pt, under the 0.75 pt KDP lists; until that changes, check them in the print previewer and in a proof copy. And go through KDP's print previewer, with any tool. Try it on the free sample.