Origami Desgin Secrets

When it comes to technical origami designs, Origami Design Secrets by Robert Lang is a must have. This 500+ page book is not like other origami books. Instead of showing you how to fold origami models, it teaches you techniques so that you can create your own models. There are a few diagrams, but these are included as an exercise to reinforce the discussed techniques.

What are some of these techniques?

Splitting Points:
Here, Robert Lang explains how a "flap" (an origami crane has 4 "flaps: two wings, one head and one tail) can be divided into more flaps. Thus, a head can be converted into a head with a beak. A leg can be converted to a leg with toes. [Photo: Goatfish uses point splitting to create a head with a lower jaw and two barbels. Folded by H Mariano.]

The idea behind grafting is to add extra strips of paper so that you can use the extra paper to make a more detailed or better model. In reality, you don't add strips of paper: you simply use a larger piece of paper. Some of the paper will be reserved for the original design and the extra paper will be used to for the elements you want to add. [Photo: Western Pond Turtle uses grafting
to create the pattern on the shell. Folded by H Mariano.]

Origami models are often composed of repeated sections which can be called "tiles". This is evident when you unfold the model and look at its crease pattern. Different crease patterns will provide different tiles. Robert Lang explains how you can assemble different tiles together to create new origami bases. [Photo: Centipede utilizes rectangular and triangle tiles.
Folded by H Mariano.]

Origami Design Secrets continues with a discussion of Tree Theory, Box Pleating, and other design concepts. I highly recommend this book for those who want to use a technical approach to design origami models.