Hidden Compartment Book

For this Instructable, I wanted to make a book with a hidden compartment, while still making a book that’s usable. So, instead of hiding something in the paper, this design hides items in the cover. It’s a great place to store small items, such as a credit card or note.

I heavily relied on Sea Lemon’s videos for how to bind and create text blocks for books. I didn’t follow her instructions exactly, but used them as an inspiration.

For making a text block: https://www.youtube.com/watch?v=XGQ5P8QVHSg&list=UUGbxOeCBuGSsKvt4g9lEv3A

For case binding: https://www.youtube.com/watch?v=Av_rU-yOPd4&t=2s

For creating a book cover: https://www.youtube.com/watch?v=HOKS0-SOqss

Materials:

• Standard printer paper - I used 15 sheets (the more paper you use, the more pages your book will have)
• Colored card stock - about 3 sheets
• Fabric or fake leather for the cover - I used some felt-like fabric - 12’’ by 8 ¾’’ - you’ll want it to be 5mm taller than your book. The width will depend on how large you want the flaps to be, but it needs to be at least as wide as your book when it is fully opened
• Cardboard - how much depends on how large your book is - I just used scraps from delivery boxes
• Thread - I used black for binding, and blue for my cover
• Glue - I used Elmer’s School Glue, but it would probably be better if you used book glue

Tools:

• Sewing needle
• Heavy objects such as books or a book press (to weigh our book down while drying)
• Cutting surface such as a cutting board or scrap cardboard
• X-ACTO blade or scissors
• Ruler

The first step in making your book is making the hardcover, including that secret compartment.

I didn’t want to make a large book, so I took some scrap cardboard and cut it into four 4 ½’’ by 5 ½’’ pieces. You’ll use one for the back cover, and three for the front. You could also make the back cover the same thickness as the front, if you prefer.

I also made the cover the same height as the paper - it’s also possible to oversize this if you prefer.

Two of your cardboard pieces are done. One of these will be used as the bottom piece of the front cover, and the other will be the back cover.

For the front side, we’ll need to make some additional cuts. Take one of your pieces, and cut out the center, leaving a 1.5 cm border around the outside. This will be the compartment, aka the middle piece.

Finally, we need to cut the “lid”. Cut three of the sides like you did before - 1.5 cm margin, on the two short inner borders, and one long. Cut all the way through. On the final edge, only cut about ¾ of the way through the cardboard, leaving the top layer of cardboard intact. This is our “hinge”. Make sure it works and doesn’t stick - you may need to cut the other sides a bit wider to make it looser. This piece is our top piece.

We have all our pieces! Now it’s time to glue them together. For the back cover, this is simple - just glue some of your cardstock on one side (we will do the other side in a later step). For the front cover, first glue the bottom and middle pieces together, then very carefully fold and cut a piece of cardstock to fit within the cavity. This is much easier to see in the photos. Glue in place.

Finally, glue cardstock on both faces of the top piece, and very carefully cut along where the cardboard is cut, so that you once again have a “hinged” cardboard piece. Make sure it still functions, then glue on top of the middle piece, making sure the hinge is oriented so that the compartment will still open.

I made my pages out of ¼ of a standard (8.5'' x 11'') printer paper. Start out by folding the paper in half both ways. Then, cut along your fold that intersects the 11’’ edge. I found that an X-ACTO with a ruler works better than cutting with scissors, in order to get a straight line. Make sure you’re cutting on a surface such as a cutting mat or scrap cardboard!

Repeat this 15 times. This gives you 30 pieces of paper, and 60 pages total. Take your pages, and group them into signatures of 6 cut pages by placing one inside the next. You will end up with 5 signatures, of 12 pages apiece.

Next, we need to sew the pages together. Rather than try to explain this part, I will refer you to the text block tutorial above - it’s a lot easier to understand through a video than it would be through text.

Now that we have our block sewn together, the next step is to glue it and add end pages and the hardcover.

First, take some time to align the text block with itself, so that the book will be straight. Then, secure the text block. I used a heavy book, with a magazine underneath to catch any glue drips. Apply a layer or two of glue on the spine, and let it dry. I used my finger to smooth it, but you could also use a paintbrush.

Take a piece of your card stock, and fold it in half both ways. Cut along the fold that intersects the 11” edge, as you did for your book pages. These will be our two sets of end pages.

Apply a layer of glue on the top text block page next to the spine, about ¼ inch wide. Again, smooth with either your finger or a paintbrush. Secure one end page onto the glued area, making sure to line it up with the spine of the book. Repeat on the other side of the book. Secure under your book or other heavy item, and let dry.

If you wanted to, at this point you could square up the pages by using a ruler and a blade, but I wanted to keep the edges rougher, so I left them as-is.

Take an end page, and glue it to the side of back cover that is still bare (doesn’t have cardstock glued to it). Do the same for the front cover. Make sure to smooth out the glue before you place the paper, otherwise the paper will warp and wrinkle. Again, place this under something heavy to dry.

Now that we have a completed our text block, it’s time to add the book cover! This is what will hide our secret compartment.

First, cut the felt cover to the correct height. The height should be 5mm + the height of your book (to leave room for the stitching).

I used a piece of felt-fabric that was already about the length I wanted, so I did not need to cut my material down at all. If yours is larger, you might want to, depending on how large you want your flaps to be.

Next, we need to mark out where we want to sew. The width of the spine of my book is 13/16 in, so I centered that difference on the long edge of my felt. I did this by marking the halfway point (6 inches), and then marking half of 13/16 inches on either side. This is where the spine will sit.

Carefully lay your spine in this position, and tilt the book to one side, and wrap the cover around the book. Mark out where this fold is on the top and bottom of the book. Do this to the other cover of the book. This marks out where we will be sewing.

Now, tape the flaps in place, based on the marks you just made. Leave some room at the edge so you can sew.

Take your thread, and sew along one edge of the flap, sewing it together. I sewed to the end and back, to get a nice “x” pattern (you can see this in the pictures). When you get back to where you started, knot the thread and cut off any excess.

Repeat this for the other three flap edges. I found it helpful to check the fit after I had sewn one side, to make sure everything still fit right. Once you have sewn all four edges, your book cover is complete!

Carefully work the book cover onto the hardcover of the book. I found it easiest to fit the flap on the front cover first, then the back cover. If you lay the book almost open, it’s fairly easy to slip the cover on (see pictures). If your cover doesn’t quite fit, depending on the material you used, you may be able to stretch it a bit.

Congratulations! You now have your very own hidden compartment book!

I have so many ideas for improvement, such as:

• Binding the cover with the text block to better secure it
• Making the edges of the book look better, since right now you can still see the cardboard
• Adding a handle of some sort to make the compartment easier to open

Maybe someday I'll get around to making a second version of this that incorporates some of these ideas.

Please leave any thoughts, suggestions, or questions below, and thanks for reading!