In traditional Japanese culture, origami referred to the ceremonial folding of paper certificates. Over time, the folding of paper developed into an art form of its own. There is a long tradition of folded paper patterns that are handed down along the generations, often with each new designer adding specific twists and embellishments. The art of paper folding has a specific significance in education. When Friedrich Froebel founded the first kindergarten in the mid-1800s, his educational plans and theories included paper folding as a way to teach children basic concepts of mathematics and symmetry. When Imperial Japan reopened its borders to trade, these basic folding techniques found their way back to Japan where they were adopted into the traditional educational model. While many Western schools have abandoned some of the traditional lessons on paper folding as part of basic learning, the Japanese have retained those models in their traditional kindergarten and primary school curriculum.