Origami

Origami turns a flat sheet into a two- or three-dimensional form through a sequence of folds. Many contemporary designs are made from a single square sheet without cutting, but the practice also includes modular work assembled from several folded units, composite designs that use multiple sheets, and forms that permit cuts. Instructions commonly use crease diagrams and symbols to show how a model is folded, allowing designs to be learned and reproduced across language barriers. Folders use techniques that range from simple geometric creases to wet folding, in which dampened paper can be shaped into softer curves.

The earliest history of paper folding is difficult to reconstruct because written and physical evidence is sparse. Origami is strongly associated with Japan, but historians caution that the art's beginnings are uncertain and that paper-folding practices may have developed in more than one place. In Japan, formal paper-folding and wrapping traditions were used in gift exchange and ceremony; an illustrated album in the Metropolitan Museum of Art records origata models in 1697. The word “origami” combines the Japanese words for folding and paper and came into wider use for recreational folding in the late nineteenth century. Akisato Rito's 1797 book Sembazuru orikata is among the early printed instructional works, showing ways to fold linked paper cranes. In the twentieth century, folders including Akira Yoshizawa helped bring new designs and diagramming conventions to wider audiences, and the practice developed an international following.

Origami is not a single visual style. Some models reduce an animal or object to a few characteristic folds; others aim for detailed, lifelike forms. Modular origami connects repeated folded units into larger structures, while tessellations use recurring crease patterns to create surface designs. A model can be planned as a sequence of folds or developed from a crease pattern, and the choice of paper, scale and folding method affects the result. The crane is one familiar model, but folders also create plants, animals, geometric forms and abstract sculptures. Traditional and contemporary practices overlap, and new techniques continually expand the range of forms that can be made.

Researchers have adapted origami's geometry and folding motions to designs made from materials other than paper. A scholarly review surveys work on foldable structures in robotics, architecture, biomedical engineering and space systems. Folding can let a structure occupy a compact shape for transport and then deploy into a larger form, but translating a paper pattern into a working device requires attention to material thickness, stiffness, hinges, actuation and reliable deployment. NASA's Jet Propulsion Laboratory describes a starshade concept that would fold for launch and unfold in space to block starlight for a telescope seeking to image exoplanets; this is an engineering concept, not an example of a deployed origami spacecraft. Such work shows how a traditional art can inspire technical designs without making every research prototype a practical or proven device.