1. Crop the canvas
Back buckle the canvas on a clean and flat ground or table, place the inner frame on the canvas, the four sides of the canvas are larger than the inner frame by a side, and the thickness of the side of the inner frame is slightly more. Be sure to align the latitude and longitude lines of the canvas with the four sides of the inner frame, otherwise the slanted cloth will affect the texture and beauty of the picture, and may also skew the four corners of the canvas. After drawing the crop line, cut the canvas.
Second, the wet canvas
The cotton canvas and the canvas that has already been made have different expansion and shrinkage ratios before stretching the cloth. Wet the back of the canvas evenly with water to make it swell and expand. When wetting the canvas, it is necessary to grasp the proper size and timing, too much water is easy to degumming the substrate. After the canvas is stretched on the inner frame and dried, the contraction of the canvas will make it tight and flat. Wet stretched canvas can be carried out on rainy days. The performance of linen cloth is opposite to that of cotton cloth. It shrinks when wet and relaxes after drying, so the unlined linen cloth should be stretched, and it should be stretched in sunny and dry weather as much as possible. The contraction performance of different canvases varies greatly, so we should pay attention to accumulating experience in practice.
3. Nail canvas
First temporarily fix the prepared canvas with a few nails or pushpins on the inner frame. Pay attention to the sloped side of the inner frame facing the back of the canvas and keep the four sides of the canvas parallel to the inner frame. A nail should start from the center of the outside of the long side of the inner frame, and then nail two on the other side, and then nail the two short sides in the same way. At this time, a rhomboid wrinkle will be formed in the middle of the canvas. Then proceed in the cross direction in the order of the four sides. When nailing, you should evenly tighten the canvas with your hands or canvas pliers. From time to time, observe whether the cloth pattern is parallel to the inner frame. Excessively tightening the canvas will tear the fibers of the cloth and the holes will be large, so that the primer will penetrate the back of the canvas, and it will make the future picture lack reasonable expansion and contraction, causing the color layer to crack. The distance between the nails is determined by the size of the frame, preferably 4 to 6 cm, which is about the width of a canvas pliers. The nail spacing of the same picture should be basically uniform to balance the force. Canvases without foundation or larger canvases may need to be tightened after being stretched, so do not nail the nails for adjustment.
Four, four corners and back processing
When the canvas is nailed to the four corners of the inner frame, fold the canvas at an oblique angle and wrap it around the upper and lower sides of the frame. Do not expose the folding pattern to the outside. After nailing the canvas, nail the excess canvas on all four sides to the back of the inner frame with a nail gun and straighten it. Another method is to directly nail the nails to the back of the frame. Some large-scale modern oil paintings are sometimes displayed without the outer frame or only the simple side strips from the side. This method is relatively flat from the side, so that The four sides of the frame are more beautiful.
Fifth, adjust the tightness
After the canvas is stretched and dried, you can check whether it is flat and whether the elasticity is even and appropriate. If appropriate, the nails can be tightened and reinforced, otherwise the heavy stretch should be adjusted or even removed in time, and it cannot be reluctantly made up. Waiting for the canvas to be stretched after painting will affect the picture.