Origami!

Origami means to fold paper, and it is the art of, obviously, fold paper :) Origami uses a small number of different folds, but when they are combined in different ways, you can create complex designs. Everything begins with a square sheet of paper, which may have different colors on each side. This traditional Japanese art, has been practiced since 1603, and in the present days, it has started new mathematical theories about folding paper (yes, math about folding paper XD) and Technical Origami, known as Origami Sekkei.
Special origami paper, "kami", is sold in prepackaged squares of various sizes ranging from 2.5 cm to 25 cm or more. It is commonly colored on one side and white on the other; also, dual colored and patterned versions exist and can be used effectively for color-changed models. Origami paper weighs slightly less than copy paper, making it suitable for a wider range of models.