I made a piano hinge book out of envelopes and bamboo skewers to fill with monsters that my family and I are making up. It’s also possible to use paper that has been folded, but I prefer envelopes so that you have little pockets to hold photos, keepsakes, etc.
First, cut the flaps off of your envelopes (I used four, but this is up to you). Stack them so that they are all facing the same direction. Using a template similar to the one below, cut out notches on the bottom edge of each envelope. I never really put measurements on it, I just eyeball it (I know, isn’t that horrible?), but it should end up looking somehthing like this:
Now, take a bamboo skewer and weave it in the first notch of the first envelope, the second notch of the second envelope, then back to the first envelope, and so on until you reach the end. Repeat this step to connect the rest of the envelopes together. When you finish, you will have extra tabs on the front and back of your book. Weave a skewer through these to finish them off. You may want to amputate the pokey ends to keep from skewering yourself, but it is much easier to weave the skewers through your envelopes using the sharp end, then cut it off later. The skewers may slip and slide on your binding, so finish them off by winding some fibers around the ends and tieing them tightly to help keep the skewers in place. I chose some hairy brown eyelash yarn to go along with the monster theme of my book. When you finish, your binding should look like this:
Now decorate your book to your heart’s content. I put little tabs on each of my monster photos to make it easier to pull them out of each envelope.