The book box above was adapted from a Japanese card structure that I first saw in an old book I have called Creative Cards by Yoshiko Kitagawa, Kodansha International 1987. The book and box above were also made a long time ago in 1997.
I used the card structure for my 2012 Christmas card and I will show how I adapted it into a book box. The pattern for the card is based on a square with semicircular flaps.
The flaps are folded over consecutively and when you fold the last one you need to tuck it in under the first one and it looks like this.
The finished book box will also look like that.
I added the width of the book's spine to the pattern to create a box structure.
1. The inner square should be the measurement of the book plus 4 mm.
2. The width of the book's spine is added to create an outer square.
3. A semi-circle is then added to each side and its diameter is the same length as the side of the inner square.
4. The little squares on each corner are used as tabs. You cut through the outer square on one side of the tab, and fold it on the other side and glue it to the wall of the adjacent side to form the sides of the box.
5. The semicircular flaps will then fold in as they did with the card and it will have the same appearance except that it has depth rather than being flat.
(Thanks Di for inspiring me to write this post.)