The structure of one of those thick composition books seems pretty straightforward. It is just a big thick pamphlet. I wondered though whether there would be tricks and techniques to making one. I decided to give it a try. I think it worked out well, so wanted to share what I learned.
Step 1: Cover Materials
You'll want some thick decorative paper for the inside and outside of the cover. I like a strong handmade paper for this. To make the covers stiff you'll want some board as well. I'm using a single ply matte board here. The edge of the board is going to be visible so I liked the white colour of the matte board rather than a grey binders board. And then for added strength at the spine use a piece of book cloth.
Step 2: Attach the Outside Paper
You could use paste or glue stick. I used paste.
I found it easiest to first paste the outside paper to the board. I put the paste on the board to minimize warping.
Step 3: Attach the Boards to the Inside Cover
Then I paste the board to the inside paper. Again I applied the paste to the board rather than the paper to minimize warping.
Step 4: Attach the Cloth Spine
I put the paste on the cloth for this.
Once it is all pasted together let it dry between boards to keep it flat. Dry it for a bit wrapped in wax paper and then you can switch to using blotters to help it dry quicker.
Step 5: Make a Template
I made a template for drilling the holes that I'll use to sew the book together.
Step 6: Set the Template in Place
The gap between the front and back cover boards along the spine keeps the template solidly in place. The pictures don't show it here, but at this point you've got your text block (the papers that make up the inside of the big pamphlet) underneath the cover so that you are drilling through both the cover and the text block at the same time.
Step 7: Determine How Far to Drill
I put a piece of tape on my drill bit so that I know how far I need to drill through. I just put a pile of scrap binder's board underneath it all to avoid drilling into my work bench. That is important to do even if you don't care about your work bench since the right speed for drilling through paper/board is not the right speed for drilling into wood.
Step 8: What the Outside Will Look Like
Once the holes are drilled, the outside will look like this
Step 9: What the Inside Will Look Like
Once the holes are drilled, the inside will look like this
Step 10: Sewing the Book
I started from the inside using all the holes.
Step 11: Continue Sewing
And then back to the top.
Step 12: And Another Layer of Thread
Go back to the bottom and up to the top again, so that there are two layers of thread everywhere on the outside and inside.
Step 13: Tie the Two Ends Together
Finish the sewing by tying the two ends together
Step 14: Folding
Once you've finished sewing you can fold the papers in half and have something that finally looks like a book.
If you look at the picture, one of the things you will want to care about a bit is to make sure that as you fold you are pulling the cover taut so that it follows the same shape as the inner text block. I didn't even think about this with my first one and it worked fine.
Step 15: Optional: Making Press Boards
I made press boards that have a piece of that one ply matte board (the same that I used for my cover boards) which allowed me to be applying pressure to the spine directly when I was pressing the book. I'm not sure that was necessary, but once I made the boards I've just kept using them.
Step 16: Keep It Under Weight
The books are probably best kept under weight for a few days to get them really comfortable with their new shape.
Step 17: Trimming
I failed to take before pictures of this step. But you'll find that your pamphlet will have uneven paper at the fore edge and probably along the top and bottom. Trimming each of those edges will provide a much cleaner finish for the book.
A few years ago I treated myself to a http://www.louet.nl/en/bookbinding-vertical-plough which makes that trimming fun. It is an extravagance that you definitely don't need. There is lots of good info on trimming on the web. I'd suggest googling "how to trim a book block".