Book folding with line templates: a complete guide

In my previous article, I shared how I fell down the rabbit hole of book folding. As promised, here is a complete tutorial on how to create your own book-folding art using a simple technique that I call “line templates”.

To generate the line template, we’ll be using a free tool I built specifically for this:

✨✨ ⮕ bookfold.derlin.ch ⬅ ✨✨

Jump to the conclusion to see the final result.

#Requirements

Mandatory:

• A printer and an internet connection.

• A hardback book with at least 161 physical pages (or 322 numbered pages), ideally a few dozen more.

  Caution

  A book with 320 numbered pages actually has 160 physical sheets of paper (leaflets). Moreover, most books do not start the numbering at 0, so be mindful when counting your pages.

• Scissors.

• A pencil (that is ideally easy to erase).

• Some spare time 😉.

Nice-to-have:

• A ruler 1 to 1.5 cm wide.
• A bone folder (Teflon ones are the best for crisp lines).
• A small piece of cardboard (to help manage the pattern).
• An eraser.

#1. Find a good image

First, you need a design. I usually browse Pinterest for inspiration, looking specifically for “black and white”, “silhouettes”, and “stencils”. The more details, the higher the number of pages you will need. You will have to play with the tool (and the process) multiple times to build your intuition on what works and what doesn’t.

For this tutorial, we will create a combi fold using this flower design:

#2. Generate the pattern

Navigate to bookfold.derlin.ch. It’s a totally free line pattern generator I created to make everything easier. Piece of advice: it easier to use on desktop!

#Processing the image

Save the flower image above and upload it in bookfold.derlin.ch using the Source panel on the left. The tool will automatically trim the empty pixels and convert it to black (design) and white (background).

Optionally:

• Resize Image: Adjust the size (in percent) to fit your vision. This directly impacts how many pages you’ll need to fold. For this tutorial, I resized the image to 90%.
• Black/White Threshold: If your image is a bit “noisy” or grayscale, play with the threshold (default is 128) to decide exactly what becomes a black segment and what stays white.
• Inverse colors: Useful if you want the “background” to be popping up instead of the “design”.

#Fine-tuning the pattern

The tool scans your image horizontally and takes samples every few pixels.

• Line spacing: This is the most important setting. A higher spacing means fewer details but also fewer pages to fold. For this tutorial, I used a spacing of 4.
• Horizontal Stretch: This makes the printed pattern easier to read by “stretching” it sideways. It doesn’t change the final look of the book, but it saves your eyes from squinting! 1 means 100% (no stretch at all). I usually set this to 1.5.
• Line Thickness: I recommend 2 pixels, so the segments are clearly visible once printed (make it even bigger on cheap printers).
• Padding: This adds some padding around the design, so the helper lines are always visible. I usually set it to 10 pixels.

#Exporting

Once you’re happy, check the Pattern Info at the top. It will tell you exactly how many lines (physical sheets) and pages (numbered pages) will be required.

If you followed along, you should see 161 lines, which means a book with at least 322 numbered pages (again, beware of the page numbers, they do not always start at zero!).

#3. Select and prepare your book

Now, you need a book that matches your pattern.

• Page count: Our pattern needs 322 pages. Look for a book with at least 340+ pages to give yourself a safety margin at the beginning and end.
• Colors: Avoid books with colored or glossy pages. If there are just a few interspersed here and there, remove them before you start.
• Paper quality: Avoid books with very thin paper; they don’t hold the “pop” of the fold as well, and you risk tearing them during folding. Also be aware that the thicker the paper, the heavier the resulting book fold. If it is too heavy, it might not stand up on its own.

Once you found your book, measure the height of a single page (e.g. 20 cm).

#4. Print the pattern

The pattern needs to be printed at the right size and at the right offset (so the design is centered properly).

Let’s say your book pages are 20 cm tall. You want some margin at the top and bottom of the design: 2.5 cm is usually a good value, so the design should be 15 cm tall (20 - (2 x 2.5)). To center it, you’ll need a 2.5 cm offset from the top.

In other words, you need to print the template on a landscape A4 paper, 2.5 cm from the top and with an height of 15. There are multiple ways of achieving this, but here is my “pro” workflow for printing:

1. Copy the template from the tool (right click > copy) and paste it into a Google Doc (docs.new).

2. Set the page orientation to Landscape.

3. Click the image and open Image options:

   • Under Size & Rotation, set the height to 15 cm.
   • Under Position, select “Fix position on page” and set the offset (relative to top left of page) Y to 2.5 cm.

#5. Compute the start page

To center the design within the book, we need to find the right starting page. The book I am using has the first page numbered 5, and the last page numbered 357.

1. Find the usable range: (last page number) - (first page number). For me: 357 - 5 = 352.
2. Subtract the pattern pages (322): 352 - 322 = 30 spare pages.
3. Divide by two for the margins: 30 / 2 = 15 pages.
4. Add the offset: since the book starts at page 5, my first folded page will be numbered 5 + 15 = 20.

I usually start one or two pages earlier (page 18 in this case) to have some spare if I make a mistake.

#6. Let’s fold!

#Step 1: Mark the pages

Place the pattern behind your first page. Align the top of the pattern with the top of the book, and the first vertical line with the edge of the page.

Draw small marks at the start and end of every black segment using a pencil. When you’re done with a line, draw a dot at the top of the pattern line on your template to mark your progress (so you know where you are).

Head over to the second page and repeat. Do this for the batch.

#Step 2: Fold the edges

Go back to the first page you marked. Fold the top-most and bottom-most marks all the way to the book’s binding. If there are marks in the middle, leave them for now; those are for cutting.

#Step 3: The helper line (optional)

Draw a faint vertical line about 1.5 cm from the edge of the page. This is your “stop” line. It ensures all your cuts are the same depth, which makes the final result look much more professional.

Having a ruler of about 1.5 cm wide in this step is quite helpful 😉.

#Step 4: Cut and fold

For all the marks in the middle of the page (all but the first and last marks):

1. Cut horizontally from the mark to your helper line. Try to keep the cut as straight as possible!
2. Fold every other tab back toward the binding. The rule of thumb: the very top and very bottom sections are always left unfolded.

#Step 5: Repeat

Repeat this for every page in your pattern, batch by batch, and watch your design slowly emerge from the pages!

#Conclusion

How does your final book look like? Here is mine:

If you’re looking for more inspiration, remember to check out my introduction to book folding for more variants, techniques, and ideas. And if bookfold.derlin.ch has proven useful to you, feel free to share it around (I would like it very much 😊).

Happy folding!