Silk-screen print handmade (top)

Screen-printing is a creative work combining art, technology, and materials. Platemaking plays a key role in it. It is a prerequisite for ensuring the quality of subsequent printing. Since most screen-printing enthusiasts do not have the equipment for professional screen printing, mastering the plate-making skills under manual conditions is particularly important. Below I talk about my own experience.

1. Wire mesh

Wire mesh is the first element of making silk screen prints. Today's screen prints generally choose seventeen fiber webs, of which the nylon mesh surface is smooth, the ink passability is good, and the screen has strong resilience and is suitable for printing with color blocks. The main picture. Polyester mesh has high tension level, low elongation, and strong stability. It is suitable for printing fine silk screen prints.

The mesh number of the screen indicates the density of the mesh weave, which refers to the number of meshes (mesh) or screen lines per unit length. Screen printing generally choose 100 ~ 300 mesh screen, low-mesh screen mainly for color printing, high-mesh screen mainly for the point, line printing.

The choice of wire mesh should also pay attention to the thickness of wire mesh weaving and wire diameter. Single-strand flat-woven screens are good for prints, and the diameter of the wire diameter should be moderate. Too fine tension difference; Too rough mesh, ink passing poorly.

There are two types of screens, white and yellow, and it is best to use a yellow screen to make fine screen prints with photographic methods. The yellow net can prevent the diffraction caused by strong light and ensure the clearness of the plate making.

2. Frame

The frame is a kind of bracket for fixing the screen, and it is required to have sufficient strong Tang, that is, under the effect of the screen tension, the frame is not deformed. Although the screen-printing enthusiasts can choose from metal frames and plastic frames, under the manual conditions, wooden frames are preferred. The advantage of the wooden frame is

It is easy to make, self-defining, easy to fix the net, light and cheap; the disadvantage is that it easily deforms when exposed to water, so it is best to choose the white pine and spruce that should not be deformed when choosing the timber. Screen printing is different from the general screen printing process, so the size is arbitrary. When the frame is made, the size of the frame needs to be considered first, and then the possibility of exposure development is considered. The inner diameter of the frame should be greater than 5 cm above the print screen so that the ink will be stored during the squeegee. The larger the frame size, the greater the length of the ink to be stored. The thickness of the frame is not deformed to the degree that it can withstand the tension of the net, for example, the frame of the printing paper (80cm×60cm), the width of the frame is 5cm, and the thickness of the square is 3cm. The larger the frame, The thicker the box is.

3. Stretch net

Stretch net is a key part of the plate making system, which stretches the screen tightly and firmly with the frame. Whether the screen is stretched or not is directly related to the printing quality of the screen layout. If the screen is too loose, it will not be easy to rebound when it is squeegeed. The screen is pasted on the prints. The screen is lifted off, and the impressions on the prints should not be left. Stretch nets are not as tight as possible. Tension is too large and exceeds the elastic limit of the screen. The screen will lose its resilience, and it will become brittle and even tear. The principle of stretching nets should be neither loss of elasticity nor elongation. Manual: The simple strength and method of measuring the quality of the stretch net are as follows. Touching the screen with your fingers, the screen is both strong and elastic. Because screen printing is difficult to make profit, most fans are interested and the machine stretches are generally difficult to carry out. Here are a few examples of possible manual stretching methods.

(1) Unmanned wet-web method utilizes the different extensibility of wet and dry screen mesh. The cut screen mesh is wetted with water and covered on the frame. The four sides of the cut-out screen are larger than the screen frame by more than 5cm to facilitate the pulling of the net. Use force. The latitude and longitude of the screen should be perpendicular to the frame. The meridional direction of the wire mesh is preferably the same as that of the mesh frame, because the wire mesh is better in the tensile strength. When pulling the net, first pull and fix the mesh of the segment in the frame, and then stretch and fix the screen in the corners of the frame, and then stretch the rest. Stretched wire mesh can be fixed with a thumbtack first. After the wire mesh and the mesh frame are allowed to dry, the wire mesh and the frame can be adhered by using a glue that is firmly bonded. The cementing process is best - open the hair dryer while using a row of pen rods to drive the glue floating on the mesh screen into the mesh of the mesh and firmly bond it to the mesh frame. During the process of blowing the hair dryer, the damper should have a distance of 5cm from the screen and swing slightly along the direction of the mesh frame. The outlet is too close to the screen and it will roast the screen. Unarmed wet net method is a very low cost stretch netting method, because its pull strength is not enough, and it is also uneven, and it is only suitable for the monochrome silk screen printing.

(2) Iron rod rotation method Welding a steel bar with a length greater than 3 cm on the side of the frame, two handles, and a diameter of about 1.5 cm. Place the cut mesh on the frame and place it on a relatively stable work bench. Cut the screen first with a "sticky" and other glue solid one side, the other three sides of the screen should be greater than 8cm above the frame. When the net is stretched, the opposite side of the fixed net is first bonded to the steel bar with tape every 2 cm, and then the tension generated by the rotation of the iron bar and the top edge of the frame is used to achieve the goal of tight netting. . After the screen is tightened, it is coated with “sticky” along the edge of the frame, and the screen is tightly adhered to the frame under the action of the hair dryer and the row of pen bars. When the left and right sides of the screen are rotated, care should be taken that the two places near the corners of the frame should be properly relaxed so as not to tear the screen. The effect of twisting and pulling the net of the steel bar is better than that of the hand wet net method, but two people are required to cooperate. One of them presses the frame to stick the net, and the other hand holds the iron bar to rotate the net. Due to the fact that the force is not uniform enough, the iron rod rotation method is still not ideal when making well-made silk screen prints.

(3) Clamp force is the most common method of manually stretching the net. The main tools are a screen clamp (also known as stretch clamp) and a stretch net nail gun (commonly used stapler strength is not enough , not easy to choose). Before the net is stretched, the net is cut to be more than 3 cm above the net frame and covered on the net frame, and then it is nailed from one side of the net frame. When nailing the net, pay attention to flattening the edges of the net. After the wire mesh on one side of the frame is clamped, the clamp is used to clamp the middle side of the screen and clamp the side nail. Each time the net force is applied to be uniform, the density of the nail nets is better than the density. The remaining two sides of the screen are tightened by the same method. The clamp pinning method is still difficult to ensure the printing of high-quality silk screen prints, because it is difficult to achieve uniform force.

(4) manual puller sticking net method Manual pull net each clip 25 cm (general coastal towns or mainland cities for sale), is a more professional screen printing stretch net tools. It takes at least four to purchase a manual puller, and eight is generally enough, because screen prints are usually less than 100 cm. When the net is stretched, the screen is first cut into four sides larger than the net frame by 5 cm, and then the clip of the net puller is opened to clamp the screen and reach the top of the net frame. Each puller is spaced 1 cm apart. Stretch the net on one side of the net to try to synchronize force (if the net puller is not enough, you can use "sticky" and other glue fixed side). High-precision screen-printing is best pre-tensioned, and then re-stretched after the screen is relaxed. After the net is stable, use your fingers to try the net effect. If the net is firm and flexible, you can fix the net. When the net is fixed, the adhesive is glued along the edge of the frame to form a strip shape, and then the row pen is pressed under the shaking blow of the hair dryer so that the screen and the frame are firmly bonded. The method of manually pulling the net to stick the net, whether it is the pull net strength, or the uniform degree of exertion is better than the above other manual stretch nets, and a person can complete it alone, is a reliable stretch net method.