Because paper-cut works are cut out or carved out on paper, we should take the method of hollowing out. Because of hollowing out, paper-cuts with public lines must be connected with lines, and paper-cuts with bus lines must be disconnected with lines. If you cut off some lines, the whole paper-cut will be fragmented and deformed. Thus, there is a structure that does not fall or cut. This is an important feature of the art of paper-cutting, which pays great attention to lines, because the picture of paper-cutting is composed of lines. According to practical experience, the lines of paper-cutting can be summarized into five words: "round, sharp, square, missing and line". Requirements: "Round as autumn moon, sharp as wheat awn, square as blue brick, lacking as sawtooth, walking like beard." It can be said that lines are the basis of paper-cut modeling.

2. The patterning of composition modeling

Paper-cutting is different from other paintings in composition. "It is difficult to show the overlap of three-dimensional space, scene and image, and it often breaks through the proportion and perspective relationship between objects and images. The content is mainly based on the connection of images, and more combinations are used. Due to the exaggerated deformation in modeling, it can also use some laws of formal beauty of patterns to make symmetry, uniformity, balance, combination and continuity. It can arrange the sun, moon, stars, birds and clouds on the same picture, just like buildings, people and animals on the ground. Common ones are "layers of high bases" or "borrowing things for scenery".

3. The image is exaggerated, concise, beautiful and full of rhythm.

Due to the limitation of tools and materials, it is required that paper-cutting should not only grasp the characteristics of the object, but also link the lines with nature when processing images. Therefore, we can't adopt naturalistic realism. It is required to pay attention to the main part of the image and boldly give up the secondary part to make the main body clear at a glance. The figure should be prominent, forming a simple and generous aesthetic feeling, the posture of the object should be exaggerated, the action should be big, the posture should be beautiful, just like the appearance on the stage, full of rhythm.

4. Simple and bright colors

The color requirements of paper-cutting are simple and complicated, and less configuration of the same color, similar color and adjacent color. Seek harmony in contrasting colors. At the same time pay attention to the proportion of colors. If a main color is used to form the main color, the contrast of other colors will be weakened to varying degrees. Sometimes when the colors are juxtaposed and feel a little stiff, they are put in black respectively. In the main manuscript of the golden section, you can get a harmonious and lively feeling.

5. Knife should be "steady, accurate and skillful"

Many characteristics and styles of folk paper-cutting are due to certain knife skills, such as "Hundred Flowers Map" created by Zhang Yongshou, which is used in many places. For example, a chrysanthemum engraved with "arhat beard" is straight when it first opens and curled when it is in full bloom, forming a spiral circle. When cutting this kind of chrysanthemum, it needs to be cut from the inside out, and the petals can curl freely after cutting, so as to form a chrysanthemum with unique image and flavor.

If you carve a kind of chrysanthemum called "Egret Feather", because when it blooms, one petal is covered with another petal, and the other petal is hooked with another petal, you should use the "cutting method" to cut this chrysanthemum. The cut parts should be connected one by one, and the petals should follow one by one, so that the petals can vary in thickness and size, and the cut flowers can be as full and beautiful as the feathers of egrets.

When carving a large number of paper-cuts at the same time, in the use of knife method, whether it is cut or not, the cut paper-cuts should be thick. When using a knife, you must cut it up and down like a hacksaw in your hand, and the force should be rigid and even, otherwise the knife will lose its flexibility thousands of miles away. Be careful not to swing back and forth from left to right. Hold the knife vertically up and down, and the carved paper-cut will be accurate. When cutting paper, both cutting and lifting should be accurate, especially where the knives are connected. Just say it and you can cut it. Here we go. Otherwise, the lines are easily cut or torn by the knife.

"Qiao" here mainly refers to the "sawtooth" and "crescent" carved with a clever knife. These are two very important knife methods in paper cutting. If these two knife methods are used properly, the unique "knife-like paper feeling" of paper-cutting art can be formed.

Let's talk about the application of these two knife methods in detail.

"Sawtooth" is naturally produced by the author due to the cutting movement of paper and knife in the production process. It uses the ratio of length, density, straightness, rigidity and softness of sawtooth, and combines the characteristics of different objects to express its texture, sense of quantity and structure.

When carving plants, soft sawtooth patterns can show their flowers and fruits, while hard sawtooth patterns can show the needling and plush of leaves and stems of trees.

When carving animals, fine sawtooth patterns can show soft fluff, thick sawtooth patterns can show hard mane, and circular and semi-arc sawtooth patterns can show feathers and scales of birds, fish and insects.

When carving characters, we can use jumping sawtooth patterns to show moving eyebrows, beards and hair, and use slender and rich sawtooth patterns to show children's plump skin.

"Crescent Moon" is also a variety of arc-shaped decorations naturally produced in the process of cutting and carving. Gravure carving is the main way to show the lines of characters' clothes or destroy large black areas. According to the characteristics and shape of the same object, it can be long or short, wide or narrow, curved or straight, and can be changed into various types.

The two forms of "sawtooth" and "crescent" are often used alternately in different paper-cut pictures, making the levels more distinct and varied.

Sawtooth and crescent sprouted from the paper-cutting techniques of "Ma Dui Group Painting" and "Monkey Group Painting" in the Southern and Northern Dynasties. After a hundred years of historical evolution, they have continued to this day, becoming the law of decorative patterns that people love and use.

Besides "sawtooth" and "crescent", there are other forms of folk paper-cutting, such as flowers, vortex patterns, moire patterns and water patterns.