Origami is the Japanese art of paper folding. In modern usage, the word "origami" is often used as an inclusive term for all folding practices, regardless of their culture of origin. The goal is to transform a flat square sheet of paper into a finished sculpture through folding and sculpting techniques. Modern origami practitioners generally discourage the use of cuts, glue, or markings on the paper. Origami folders often use the Japanese word kirigami to refer to designs which use cuts.
The Yoshizawa–Randlett system is a diagramming system used to describe the folds of origami models. Many origami books begin with a description of basic origami techniques which are used to construct the models. There are also a number of standard bases which are commonly used as a first step in construction. Models are typically classified as requiring low, intermediate or high skill depending on the complexity of the techniques involved in the construction.
The discipline of origami or paper folding has received a considerable amount of mathematical study. Fields of interest include a given paper model's flat-foldability, and the use of paper folds to solve up-to cubic mathematical equations.
Modular origami or unit origami is a multi-stage paper folding technique in which several, or sometimes many, sheets of paper are first folded into individual modules or units and then assembled into an integrated flat shape or three-dimensional structure, usually by inserting flaps into pockets created by the folding process. These insertions create tension or friction that holds the model together. Some assemblies can be somewhat unstable because adhesives or string are not used.
Cooties is a fictitious childhood disease, commonly represented as childlore. It is used in the United States, Canada, Australia, New Zealand, and the Philippines as a rejection term and an infection tag game. It is similar to the British 'dreaded lurgi', and to terms used in the Nordic countries, in Italy, India and Iraq. A child is said to "catch" cooties through close contact with an "infected" person or from an opposite-sex child of a similar age.
A napkin, serviette or face towelette is a square of cloth or paper tissue used at the table for wiping the mouth and fingers while eating. It is also sometimes used as a bib by tucking it into a shirt collar. It is usually small and folded, sometimes in intricate designs and shapes.
Chinese paper folding, or zhezhi, is the art of paper folding that originated in medieval China.
The Sonobe module is one of the many units used to build modular origami. The popularity of Sonobe modular origami models derives from the simplicity of folding the modules, the sturdy and easy assembly, and the flexibility of the system.
The history of origami followed after the invention of paper and was a result of paper's use in society. In the detailed Japanese classification, origami is divided into stylized ceremonial origami and recreational origami, and only recreational origami is generally recognized as origami. However, this page describes the history of both ceremonial and recreational origami.
Lillian Vorhaus Oppenheimer was an origami pioneer from New York City. Becoming a leading figure in the art form in her later years, Oppenheimer is credited with popularizing it in the United States. She adopted the Japanese word origami instead of the English paper folding, and the foreign term became established in the English language due to her efforts.
Papyromancy is a way of divination through folding paper. Some say a true papyromancer can crumple up any piece of paper, unfold it, and predict the future from the creased lines reading the creased paper the way that a palm reader would read a person's palm. Another form of papyromancy is done by folding an illustrated piece of paper and interpreting the resulting image.
Kawasaki's theorem or Kawasaki–Justin theorem is a theorem in the mathematics of paper folding that describes the crease patterns with a single vertex that may be folded to form a flat figure. It states that the pattern is flat-foldable if and only if alternatingly adding and subtracting the angles of consecutive folds around the vertex gives an alternating sum of zero. Crease patterns with more than one vertex do not obey such a simple criterion, and are NP-hard to fold.
Eleanore Mikus was an American artist who began painting in the late 1950s in the Abstract Expressionist mode. By the early 1960s, she was creating monochromatic paintings with geometric patterns that according to Luis Camnitzer, “could be seen as conforming to the Minimalist aesthetic of the era while emphatically contradicting that style’s emotional distance and coldness.” In 1969, she began painting simple, cartoon-like images in bold, colorful strokes that anticipated Neo-Expressionism of the early 1980s. In the mid-1980s, Mikus resumed creating her abstract works. Since 1961, she has also been creating works of folded paper in which the “folds” make lines or textures that become integral to the material itself.
The napkin folding problem is a problem in geometry and the mathematics of paper folding that explores whether folding a square or a rectangular napkin can increase its perimeter. The problem is known under several names, including the Margulis napkin problem, suggesting it is due to Grigory Margulis, and the Arnold's rouble problem referring to Vladimir Arnold and the folding of a Russian ruble bank note. It is the first problem listed by Arnold in his book Arnold's Problems, where he calls it the rumpled dollar problem. Some versions of the problem were solved by Robert J. Lang, Svetlana Krat, Alexey S. Tarasov, and Ivan Yaschenko. One form of the problem remains open.
Hotel toilet paper folding is a common practice performed by hotels worldwide as a way of assuring guests that the bathroom has been cleaned.
Action origami is origami that can be animated. The original traditional action model is the flapping bird. Models of which the final assembly involves some special action, for instance blowing up a water bomb, are also typically classed as action origami. Rarer models like the paper plane and spinners which have no moving parts are included. Traditional action origami occasionally involved cuts, but modern models typically are constructed without them. Action origami are usually toys built to amuse, but some are designed to inspire wonder.
The Strange Case of Origami Yoda is a children's novel written by Tom Angleberger that was first published on March 1, 2010, by Amulet Books. It follows the story of a young boy named Tommy who is trying to figure out if his classmate Dwight's origami Yoda puppet can actually predict the future or if it is a hoax that Dwight created.
Ligia Montoya was an Argentinian paper-folding artist, who played an important role in all aspects of the 'golden age' of the international origami movement from the 1950s, from which developed modern artistic origami—that is, innovative paper-folding exploring a variety of different approaches, rather than repeating limited traditional figures.
A Froebel star is a Christmas decoration made of paper, common in Germany. In English it does not have a commonly recognised name; it can be referred to as an Advent star, Danish star, German star, Nordic star, Pennsylvanian star, Polish star, Swedish star, Christmas star, or Froebel star. It is also sometimes called a Moravian star, though the Moravian star is a general category of geometrical shapes and the sixteen tipped piece of origami is specifically called the Froebel star.
Geometric Origami is a book on the mathematics of paper folding, focusing on the ability to simulate and extend classical straightedge and compass constructions using origami. It was written by Austrian mathematician Robert Geretschläger and published by Arbelos Publishing in 2008. The Basic Library List Committee of the Mathematical Association of America has suggested its inclusion in undergraduate mathematics libraries.
