Build a 6×9 puzzle book for KDP

Start with a book someone can finish

A good puzzle book has a rhythm. The first few pages show readers what to do, the middle offers enough variety to stay interesting, and the back makes it easy to check a solution without revealing the next puzzle. Book Builder lets you work on that order after you have generated the puzzles. You can keep sets separate while you design them, then assemble the title page, puzzle sections and answer key in one project.

This walkthrough uses a 6 × 9 inch paperback interior with two puzzle types: 6×6 Sudoku and mazes. Imagine a book for adults who enjoy short puzzles on a commute or during a coffee break. Begin with generous grids and uncomplicated mazes. Increase the difficulty gradually, then end with a few challenges that still fit the same page design. The sample book includes a word search as well. Flip through it to see how different puzzle pages and solutions can belong to the same book.

Pick one audience before settling on a puzzle count. A reader who solves a page while standing on a train needs a different grid from a reader who sits down for an hour with a notebook. A small trim size can be comfortable to carry, but it gives you less room for instructions, cell labels and hands near the binding. If your audience needs large type or generous writing space, print one page first. Let the result guide your trim choice.

Plan your sections and page count

For a first project, sketch a complete interior with manageable batches. For example, plan a title page, one page of instructions, two puzzle sections with 20 puzzles each and an answer section. At one puzzle per page and two answers per page, that gives you 40 puzzle pages and 20 solution pages. Add the two opening pages and three divider pages and the draft comes to 65 pages. This is a planning example. Your exported count will depend on the actual settings and pages you add.

Write down what belongs in each section. An opening Sudoku section might use a gentle difficulty and a visible sample of the rules. The maze section might start with a compact grid and use larger grids as readers progress. Separate the two types with a clear divider so readers can skip to their preference. If you want to alternate Sudoku and mazes throughout the book, try the order on a few pages before applying it across the entire project. A change of activity can be pleasant, but an unexplained switch halfway through a section is confusing.

Use a simple inventory while you work. Record a set name, puzzle type, difficulty, puzzle count and planned position. Add a column for the corresponding answer group. If two sets are both described as “20 easy Sudoku,” give them distinct names so you can tell their answers apart. This also makes it easier to rebuild one section after a revision.

Think about page count as a result of the layout, not a target to fill with blank space. Reducing the number of answers per page improves readability, but increases the size of the interior. Putting two puzzles on one page may save paper, but it changes how much space readers have to write. Keep a copy of your draft count and update it whenever you change either density.

Choose the print setup before generating

Select your intended trim size and decide whether the interior needs bleed. Trim size describes the finished page. Bleed is relevant when artwork or a background is supposed to run to the edge after the page is cut. A puzzle interior with white margins is a good fit for this example because the artwork stays inside the page. If even one element is meant to run to the edge, review KDP’s setup for a bleed interior before exporting. The page dimensions and margin requirements differ. KDP’s trim, bleed and margins guide

Decide how much room the solver needs near the binding. The inside margin changes sides on facing pages. If you allow too little space on the binding side, a reader may have to press down hard on the book to reach a cell. Set the inside margin using the final count and print setup, then inspect an odd and an even page. The two pages should feel like a pair when viewed as a spread. Revisit the margin if the final page count changes. KDP’s paperback formatting instructions

Make design decisions with a black-and-white test sheet in hand. Light gray cell borders may look elegant on screen and become hard to see on paper. Very dark lines may make digits and route marks harder to distinguish. Choose a comfortable weight for the main grid and a visibly different weight for the inner Sudoku boxes. Keep instruction text and puzzle titles easy to find. A page should be understandable at a glance before someone starts solving.

Generate, solve and save a small batch

Open the 6×6 Sudoku Generator and make a handful of test puzzles before generating the full section. Pick the intended difficulty and use the preview to check the size and contrast of the digits. A 6×6 grid uses numbers 1 to 6 and rectangular 2×3 boxes. Make sure the instructions describe those boxes accurately, especially if you previously reused wording from a 9×9 book.

Solve one early puzzle the way a reader would, without looking at the answer. Note whether the printed grid leaves enough room to write a digit and erase a mistake. Try a puzzle from the middle and another from the end after you generate the full set. If an “easy” section feels inconsistent, separate the harder pages into a challenge section or generate a fresh set. Keep the naming clear enough to recognize the approved version later.

In the Multiple Maze Generator, create a few mazes and compare how long they take to finish. A maze that looks dense can still be quick if the route is easy to see. A small maze with several convincing dead ends can take longer than expected. Use actual solving time to decide where each batch belongs. On a test page, ask another person to find the entrance without a hint and follow the route with a pencil. Their hesitation may tell you more than another look at the preview.

Sign in and save each approved set so that it can be selected from Saved datasets in Book Builder. Keep puzzle and solution data together. Avoid making a second random batch just to supply answers. If you replace a puzzle set, replace its solution group as part of the same edit. Record the date or version in your notes if you are comparing several similar batches.

Assemble the manuscript in Book Builder

Open Book Builder and start a project for this interior. Select 6 × 9 inches before arranging the book so you can see how the pages behave at the intended size. Add a title page from Page presets and use a short subtitle that sets expectations about the puzzle types and difficulty. For an instructions page, explain the rules briefly and say where the answers are. Readers should be able to start with the first puzzle after a quick look.

Add your puzzle pages from Saved datasets. Put a Sudoku divider ahead of the first set, then add the maze divider and maze set. Look through the thumbnails as a sequence. Check that a divider sits directly before the group it describes and that there is enough space between the heading and the first grid. When a page looks crowded, inspect the actual page rather than judging from the thumbnail alone.

Choose whether to number the pages. Puzzle identifiers and PDF page numbers serve different purposes. A puzzle called “Maze 12” can be on page 31, for example. If the answer page refers to “Maze 12,” the reader can match it even after a title page is added or the page count changes. If you use page-number references in your text, update them after the last layout edit. Save the project once the puzzle order is settled.

Review a few facing pages while you are still free to rearrange them. If one side has a large grid and the facing page has sparse content, that is usually fine. Pay more attention to where hands rest when someone writes. A wide puzzle pushed toward the gutter may be uncomfortable even when it technically fits. In a compact book, several small improvements to spacing often matter more than another decorative element.

Create an answer key that is easy to use

Add an Answer Key divider after the last maze. Return to the original saved Sudoku set and add its answers, then do the same for the mazes. Match the order used in the puzzle sections. If the book has separate beginner and challenge groups, label the matching groups in the key as well. Someone checking one answer should be able to find it without scanning pages of unrelated solutions.

Choose answer density independently from puzzle density. Two solutions per page can work for this example if the digits and routes remain legible. Smaller answer grids save space because readers do not need to write in them. They still need to locate a digit or follow a highlighted maze route. Compare the answer page at actual print size and reduce the density if the markings become indistinct.

Spot-check the join between sections. Compare the first and last Sudoku answers with their puzzles, then compare the first and last maze answers. If you add or move a batch, include both groups in your review. A quick check of the transition often catches an off-by-one problem that would be easy to miss in the middle of a long list.

For a more systematic check, choose a puzzle from each section, finish it on paper and find the answer using only the book’s labels. Give the PDF to a second person and ask them to do the same without instructions from you. If they have to guess what “Solution 1” refers to, revise the headings or the numbering. The answer key is part of the reader experience and deserves the same care as the puzzle pages.

Export, inspect and proof the interior

Use Export book to download the interior PDF. Give the file a versioned name so you know which draft has been reviewed. Open the PDF in a viewer and check its dimensions and page count. Go to the title page, a page in the middle, the last puzzle, the divider and the last answer. Look for clipped text, blank pages you did not intend, puzzle labels that repeat unexpectedly and solutions that are difficult to read.

Print several representative pages at actual size. A home printer may add its own margins, so use the test mainly to assess readability, writing room and contrast. Check whether the binding-side space looks adequate by putting the sheets in a stack or holding them as a facing pair. Give the pencil test to someone who is not used to working from your designs. Ask where they would start and whether they can see the smallest marks clearly.

Prepare the cover as a separate file using the final interior page count and your selected print options. A change to answer density can change the spine, so avoid treating a draft cover as final while you are still rearranging the book. Upload the manuscript and cover to the KDP project and review them in Print Previewer. Resolve errors in the source project, export again, and inspect the changed pages before uploading the new file. KDP’s paperback formatting and cover resources

When a preview warning is unclear, use the page number reported by KDP to locate the page in the PDF and compare it with the intended layout. Check whether the issue affects one page or the whole manuscript. A single clipped title points to a different cause from content shifted inward on every page. Keep the approved PDF, saved project and set inventory together so the final manuscript is reproducible.

Solve common problems before adding more pages

The Sudoku grid is too small. Confirm the trim size, reduce the number of puzzles on that page and check whether a long heading is taking room away from the grid. Compare a single-page export with the compact layout. If the larger grid is clearly easier to solve, keep the extra space and adjust the planned count.

A maze looks fine in the preview but prints muddy. Inspect a section with several adjacent walls. Try lighter lines or a slightly larger maze on the page, then print again. If the route is hard to follow only in the answer key, change the solution styling or use fewer solutions per page.

The key starts with the wrong set. Compare the answer section with your inventory. If puzzle sections were reordered, move or rebuild the affected answer groups to match. Verify one puzzle on either side of each divider after the correction.

A last-minute edit changes the page count. Check the inside margin, any page references, the opening of each section and the cover dimensions. Export a fresh PDF even if the edit seems minor. Use the final file to confirm the printed page sequence and archive older versions separately.

The finished book feels monotonous. Revisit difficulty and pacing before adding a third puzzle type. A well-placed change in maze shape or a small challenge group can give readers variety without making them learn new rules. Try the revised sequence on a short run of pages. If the change helps, extend it to the rest of the book.

Decide when your first interior is ready

If you order a proof, mark the pages where the physical copy behaves differently from the PDF. Look closely at the smallest answer grid and the puzzle nearest the binding. A proof can reveal whether readers can write comfortably while holding the book open. Record fixes by puzzle identifier, then compare the new export against the marked copy. A second pass should confirm the fixes without losing pages or changing the answer order.

Read the book description you intend to use beside the final PDF. Count the actual puzzles, confirm the trim size, and check that the answers mentioned in the description are present. Test an opening page and a harder page with a pencil. Review facing pages for binding-side space and check that your answer labels match the puzzle labels. Then go through Print Previewer with the exact interior and cover you intend to submit.

Keep notes on what you would change in a second edition. Write down useful observations, such as the grid size a reader found comfortable or how many answers still fit on a legible page. Save those decisions with the project instead of relying on memory. When you start another book, reuse the parts that held up in print and test the puzzle-specific choices again. This gives you a repeatable production process and room to make each book suitable for its own readers.