What are the production methods of gypsum relief?

The production of relief can be roughly divided into the following aspects:

Materials: clay, sludge, wooden board, glass plate, gypsum powder, trowel.

Scribing modeling: take wooden board or glass plate as the bottom, paint mud for sketch, regard the mud board as paper, and draw a rectangle with a knife, so as to make the outline accurate and vivid.

Positioning: firstly, determine the height and depth of the relief according to the needs of the decorative subject, and the outdoor and distant decorative relief can be high; Close-ups and interior decoration should be low. The height standard of relief is called "standing position", that is, the edge of relief image is perpendicular to the vertical plane of the bottom plate, which is the ruler to determine the height of relief and the edge of the outline image of relief modeling. The establishment of standing posture enters the modeling of image details and structure, which is expressed from two aspects: oblique posture and round posture. The oblique position is strong and the circular position is too soft. In addition to positioning techniques, relief techniques also include: brush strokes, knife marks, clay sculptures, texture and sculpture modeling techniques.

Substitution: Decorative relief is different from proportional compression relief. It adheres to the strict plane sense of the relief surface, which is not only the need of visual appreciation, but also the requirement of practicality and architecture. This requirement stimulates the technology of using time to shape the relief image, not only to keep the relief surface flat, but also to achieve the effect of three-dimensional image. Clever use of light and shadow to replace it has become one of the special techniques and decorative techniques for decorative relief.

Turn-over molding: After the relief molding is completed, gypsum can be poured. 1. female die is made of gypsum (the ratio of gypsum powder to water is 1: 1). After female die is dried, it is coated with soapy water to form an isolation mold, which can be cast and molded. When pouring gypsum, avoid sudden pouring, and pour it slowly from a corner until the gypsum liquid is completely filled, so as to avoid bubbles and ensure the quality of the work.

If you want to process and color the relief, you can spray the advertising color directly, which can give people a stony effect. It can also be made into metal effect, with varnish as the bottom, and then coated with oil painting color and gold and silver powder to make it have the texture of one of the metals, and then it can be made into relief decoration.

The creative design of colored plastics needs drawing and overall consideration. It is not a simple sculpture coloring, but a combination of color and plastic, commonly known as "three-part plastic and seven-part painting". In order to facilitate painting, clay sculpture boldly omits the ups and downs of the body surface, and sometimes the surface has to be polished and polished many times. Paintings and sketches strengthen and enrich the vividness and expressiveness of sculpture images. Some decorations and props can also be made of other materials. Such as crowns, jewels, swords, etc. It can be made of wood, iron, feathers and cloth. This cooperative method of using various materials to create images in sculpture is also the characteristic of decorative sculpture.

Large colored sculptures are mostly used for Buddha statues. Its sculpture method is different from the wet mud molding method of general sculpture, but it is a one-time completion method with wood as the framework and mud added layer by layer. First add mud (grass mud), then add mud (fine sand mud), and then add fine mud (cotton wool mud). This carving method is the unique skill of China Buddha carving, and it doesn't need to turn over the mold or plaster molding.

Small colored sculptures have formed a historical school in Wuxi in the south of China and Tianjin in the north, and are widely known. The techniques of his sculpture come from large-scale colored sculptures, which are more delicate and skillful. Small colored sculptures are easy to collect and have a special taste as gifts, souvenirs, decorative family cases and cabinets.

In the vast rural areas of our country, the folk customs of holding "clay dolls", "clay chickens", "ancestors" and "avoiding ancestors" have lasted for thousands of years. This is a folk art to celebrate festivals and pray for God's blessing. These small clay sculptures are made by ordinary farmers. I have bright and strong colors, simple and rough shapes and strong decorative meaning. Red pigs, golden fish, cats and tigers covered with flowers are full of magnificent feelings and optimistic nature of China children. Folk colored plastic art is the most abundant nutrition for us to learn decorative sculpture.

Manufacture of small colored plastics;

Material: clay, clay knife, sandpaper, advertising color.

Mud refining blank: mash the clay, add water, add a little cotton silk and knead it into the required mud. All kinds of plastic knives made of bamboo and wood, commonly known as "pressure knives" and "carving knives", vary in size, with sharp, round, curved and straight shapes, all of which are subject to convenience. Mainly by hand, supplemented by knife pressing, cutting and picking, carefully shaped and concise, the local details of the image can be reserved for painting.

Dressing and grinding: in the stage of mud blank to be dried, plastic knives are often used to grind, one can be reinforced and the other can be smoothed. When dry, use sandpaper to polish the surface, intending to leave a smooth and rough contrast effect.

Painting: first use white as the background color, then brush the first color, and pay special attention to the brushwork, especially the pattern of clothes and the eyebrows of characters, so as to write freely and vividly. Gently apply egg white or transparent glue to face and eyes, and the color will be bright and clean, adding charm to the work.

The creation of decorative colored sculptures allows bold exaggeration and deformation, which is based on the apparent life and the shaped image, and can be emphasized and omitted, highlighted and compressed. Small colored plastic sculptures can be made into the form of desktop decoration or wall decoration. People, animals, flowers, birds, insects and fish, mountains and rivers can all be used as themes. A successful colored plastic work, whether colorful or simple and elegant, has the value of permanent preservation.

The following are the steps to sketch the relief head:

1, initial shaping

(1) Prepare a 50×40 cm head relief board, use one-inch or one-and-a-half-inch nails to nail the next one at different distances on the board as needed, and then make a long ring rope with thin iron wire, and wrap the nails together to fix the mud. If the relief is big and thick, you can add some crosses in the appropriate position. For larger reliefs, it is necessary to weave a lower character frame on each nail. Relief should be made of bottom plate, and the surface should be flat. The thickness of the clay plate is about 2 to 3 cm, and the relief head can be about 4 cm.

(2) Light is very important for relief painting. Generally, it is better to illuminate the light source above the relief, so that the head is clear and the shape is distinct. For the first time, you can choose the profile of a portrait to shape it. With the deepening of practice and the continuous improvement of modeling skills, you can change the angle of portrait into sketch.

In shaping, in order to avoid visual errors, the model's head, relief and the author's line of sight should be relatively on an equal line, just like the shooting essentials of "three points and one line", and every point will be "off target".

(3) The first step of concrete modeling is to determine the general outline of the head on the clay tablet plane, which is the same as the sketch. First outline the head with a long straight line, and then determine the position and combination relationship of the five senses with a short straight line. On this basis, mud is added along the outer contour line, and after reaching the basic thickness, the height is slightly divided, and the shapes of eyes, ears, mouth and nose and the thickness of the height points are adjusted.

In the process of adding mud, the outer contour will be affected, so the outer contour or peripheral adjustment should be carefully adjusted after each step, and the distinctive outer contour characteristics should always be maintained.

2, in-depth characterization:

(1) First of all, we should continue to shape deeply on the basis of the first step, and grasp four "points", namely, bone point, body height point and facial turning point. Bone points are the frame connection points of the basic shape of the head. No matter what the proportion of body compression is, the bone point should still protrude slightly above the muscle and form a soft and harmonious effect with the muscle. The combination of high point and low point forms the volume thickness, which reflects the proportional relationship of young workers' compression. In deep forming, on the basis of the basic thickness, add the high point of the head and dig out the low point, so that the image characteristics and sense of volume will be strong. If you add the high point of the cheekbone and then narrow the cheekbone, the sense of volume in the cheekbone will be obviously strengthened. The turning point of form refers to the turning point between faces. Whether to find the turning point in sketch will directly affect the facet relationship of the shape.

The forehead of human head is divided into front, side and top, which constitute the forehead body. The transition between faces depends on the anatomical structure, so we should analyze and understand the anatomical structure of the head while looking for the transition.

(2) Further adjust and shape the facial features and contours. First, check whether the decent relationship between the faces of the characters is compressed too much or does not conform to the principle of perspective reduction. The former will produce physical disgust, and the latter will make the body swell, or like a half-round sculpture, there is no sense of contraction, then the whole relief level will lose contact. In the adjustment, according to the specific situation, the decent figure is "added and subtracted" to achieve unity. Next, carefully shape the body structure of eyes, ears, mouth and nose. Pay special attention to the relationship between local physical characteristics and overall appearance characteristics when doing it. For example, the nose is relatively large. If you don't pay attention to the appearance and overall feeling, you will often make it too big, which will be out of harmony with other figures and weaken the characteristics.

3. Unified adjustment:

(1) Because the first two steps focus on big modeling and deep modeling, the model's face is square, her figure is not full enough, and her figure is not very thick. In this step, the muscles of the face are first adjusted and shaped to make the muscles of the lips and cheeks softer and more elastic. The protruding part of the bone should be relatively "hard", so as to coordinate the contrast and unity of bone and muscle. At this stage, the connection between the lower stool and the neck should be well connected, the joint of the two shapes should not be too rigid, the fat part should be broken slowly and naturally, and the shape of the whole bone below should be slightly obvious.

(2) When the head relief is almost finished, the overall modeling effect of the head can be checked by the following two methods: first, constantly changing the angle of the light source to find out whether there are any problems in the structure, shape, proportion and volume of the relief head and adjust it in time; Secondly, from both sides of the relief head, observe whether the compression of the side shape of the relief image is reasonable and whether the visible local shapes, such as eyes, ears, mouth and nose, are deformed. Generally, it is not easy to find the cause of deformation from the front view, but the problem can be found from the 45-degree side view or the near side view, and the adjustment can be made until it is completed.

(3) Correctly apply perspective principle, adjust the direction and angle of figures' turning surfaces and curved surfaces, and enhance the stereoscopic impression of relief images. This three-dimensional sense refers to the visual effect that the volume of the relief is not thick and the high point is not high, but it is higher than the actual volume because of the correct use of the perspective relationship, the appropriate turning relationship and the role of light. On the other hand, if the above methods are not considered in the adjustment, it is not feasible to make high points or dig low points by adding mud to enhance the three-dimensional sense. At best, it only thickens the volume and cannot produce a three-dimensional sense of space.

(4) The overall adjustment of the contour is particularly important in the final stage of the relief head. In the process of adjustment, the author's viewpoint should move and compare along the contour of the model's head and the relief image, find out the relationship between the contour and the local shape, grasp the characteristics, and carefully adjust and shape it. You can also use parallel, vertical, curve and other auxiliary lines to make dummy on the protruding points of the contour, so as to grasp the image more accurately and effectively. At the same time, the overall relationship between the edge of the relief portrait and the bottom plate is handled well, and a narrow slope is cut at the edge of the outline, which can not only enhance the fullness, but also make the relief and the small board naturally connect. At this point, the sculpture of the relief head is completed.