I provide childcare in my home for three toddlers and I've noticed that they really love board books with flaps that open. So for Christmas I made three customized lift-the-flap books for them. This instructable will explain how to make your own and give some tips on how to make the process a little easier.
Step 1: Edit photos
Before assembling the book you need to create two prints for each page. During step 2 you will cut through the top layer to make a flap which will reveal someone (or something) on the layer underneath. This is easiest to do with a photo editing program that supports multiple layers. (Photoshop Elements 2.0 worked fine for me.)
Note that I only printed the first two images. The second two are just to help explain how to use multiple layers for alignment. I found it helpful to cut the windows out of the top layer and place them on a separate layer in Photoshop. That way I could hide the layer with the windows temporarily while I dropped my images of mom, dad, Elie, and the squirrel onto a layer under the top layer for scaling. Since the windows are cut out and hidden you will be able to see the people through the openings and scale them to fit. Then you can turn the layer with the windows and doors on and off to test the flaps.
Once you have made the two layers for each page and a front and back cover you can print out all your prints either at home if you have a photo printer or at your local print shop. (I printed mine over the internet to the one hour photo center at Walmart.) I would recommend a matte finish which won't show fingerprints as quickly as glossy.
Step 2: Cut an old board book to size
On your way to pick up your photos at the print shop swing by your local thrift store and get a board book to use as a base. The book should be at least 4x6 inches in order to fit the prints. I cut mine down to exactly 4x6 inches to match the prints using a saber saw with a fine blade. You could also use a utility knife to cut one page at a time. I spray painted the binding black to hide the old book title.
As another alternative (which I'll probably try on my next book) you could glue the photos onto individual pieces of cardboard and then bind it yourself or take it to a print shop and get it spiral bound. Using an old board book as my base spared me from dealing with binding the thick pages but it ended up making it difficult to close the book due to the extra thickness of the four prints between pages. This isn't all bad though because it makes it much easier for a toddler to turn the pages since they stand apart.
Step 3: Cut the flaps
This is the trickiest part of the project. Take an Xacto knife or razor blade and carefully cut three sides of your doors and windows to make flaps. Make sure you have a good sharp blade in the knife and use a metal straight edge to make nice straight lines. Wouldn't a laser cutter would be handy for this task?
TIP: It's a good idea to plan your book before you start cutting so you know which images will be for left hand pages and which will be for right hand pages. Then when you are cutting the flaps always put the uncut edge toward the inside of the book. That way the flaps will automatically close when the book is closed. If you put the uncut edge toward the outside of the book (or top or bottom) you will tend to have problems with the flaps getting squashed or pressed into the open position.
Step 4: Glue the prints onto the board book
Once you have all your flaps cut you can start gluing the prints onto the board book pages. The bottom layer prints can just be sprayed and then attached to the board book but the top layer prints will need to be protected with low tack masking tape or other shielding to avoid getting spray glue on the flaps. (You obviously don't want to glue your flaps closed!) I supported my prints on wire mesh. If you just laid them directly on newspaper and then sprayed on the adhesive you would tend to have problems with the edges of the prints sticking to the newspaper.
TIP: I used 3M Super 77 multipurpose spray adhesive. It worked great for this project but I have a very important tip. Don't spray a print and then immediately try to glue it into the book. You will get glue on your fingers and then onto the print and it will be much messier and more difficult than necessary. Instead, layout all your prints and spray them all at once, then wait 5 minutes for the glue to partially dry. After 5 minutes the prints will still stick very well to paper but will hardly stick to your fingers at all.
Step 5: To finish
Most important final step: Leave the book fanned open with all the flaps open overnight to dry completely. The last thing you want at this stage is to glue your flaps shut or to glue entire pages together.
One other minor detail I added was a title on the binding. I just printed out some text on my laser printer, cut it down to a narrow strip and then used clear packing tape to attach it to the binding. I also used the spray adhesive to attach single prints (no flaps) to the front and back covers.
By the way, if the whole process of making two layers and cutting the flaps sounds too complicated, you can still make a fun custom book for a toddler by making single prints in Photoshop (like image 3 on step 1) and just gluing those onto a board book.