What is the line in the middle of the dotted line of handmade paper?

It is called a shear line or a polyline.

Usually handmade paper has solid lines and dotted lines to indicate the folding mode. The solid line indicates forward folding, and the dotted line indicates reverse folding. There are still some hand-made origami to be cut. At this time, you can follow the instructions and cut according to the tips of the dotted line.

Origami is not only an art, but also an exercise method. Origami is good for anyone. Chen Chaoying, president of the Paper Art Society, said, "origami can exercise people's comprehensive coordination ability, including hands, eyes and brain. Origami needs to look at the folding process with eyes, and think and remember the process while watching. Do it yourself when folding, and think carefully about how others folded just now when encountering problems. In this way, you can use your brain to activate your thinking, so as to achieve the comprehensive coordination of the trinity of hand, eye and brain. Origami can also enhance the feelings between people, deepen mutual understanding and make people live in harmony. In addition, folding paper into bowls and pen containers that can be used in real life is not only durable and beautiful, but also very environmentally friendly and will not pollute the environment. Origami is not a childhood toy, but a profound art, which is full of exploration and discovery, as well as many difficulties and tests. After hard work, there will be new discoveries and a strong sense of accomplishment.