Crease patterns (CP) can be a mystery! This page will answer some of the common questions regarding CP.
What are CP?
CP are the lines on a piece of paper when you unfold an origami model. There are many creases in an origami model but not all are shown in a CP diagram. Only the critical folds that form the main part of the model (called the 'base') is shown.
Some diagrammers will use red and blue lines to differentiate between valley and mountain folds. If a CP is particularly complex, shaded circles are used to show the major body parts. [Photo from Nicolas Terry]
Why do people use CP?
Why do people use CP when conventional diagrams are so much easier to understand?
- CP are easy to generate: just unfold the model, scan or draw the line patterns, and you’re done. A single image will show all the important folds in the model. In contrast, conventional origami diagrams are time-consuming and tedious to generate.
- If you want to fold an origami model and there are no conventional diagrams for it, then you must use the information in the CP to determine how the model is folded. You use the CP because you have no other choice.
- CP are fun to study. You can look at them and determine which creases are responsible for the different parts of the model. A crease pattern with two distinct regions may represent the head and the body of the model. Multiple short creases all radiating from a single point may be claws, toes, or tentacles.
- Analyzing CP can allow you to modify an existing model or design new models. [Photo below from Go Guspath]
Who uses CP?
Origami designers use CP to help create new origami models. Using paper and pencil, technical origami designers map out entire origami models via their CP. Eric Joisel uses CP to create origami models. Robert Lang’s TreeMaker is a computer program that allows you to generate CP for rather complex origami models.
Since some origami models are not diagrammed, people will fold models using the information in the CP. Anyone can fold from a CP but the diagrams are challenging to decipher and can be approached as if they are puzzles.
The process involves folding the necessary creases and then collapsing the paper into the final model. It helps if the creator has used different line-patterns to differentiate between valley and mountain folds. Shaded regions designating the different body parts are helpful too.
Folding from a CP is not simple and will require a number of tries before success. Don't be tempted to fold a complex model from its CP because a conventional diagram is not available. Start with easy models before progressing to the complex models. You can find tips on how to interpret CP in: