Sweaters have developed from hand-knitting to machine-knitting, and people's wearing has undergone great changes. From the original simple warm-keeping type to the direction of light, soft and thin, and it is more fashionable and beautiful.

Wool yarn is generally sized according to the number of needles, and can be roughly divided into three types according to the thickness: one is high and thick yarn: when knitting, the width is about 3.3 cm (1 inch) with 7-8 needles, and the length is about 8-10 needles It is about 3.3 cm, the second is medium and thick thread, the width is 3.3 cm with 9 stitches, the length is 3.3 cm with 10-11 stitches, the third is thin thread, the width is 11 stitches is 3.3 cm, and the length is 3.3 cm with 12-14 stitches centimeter. When knitting patterns with these three kinds of threads, there will generally be an error of 1-2 stitches, so stitches should be appropriately increased or decreased according to the density of the pattern.

The composition of sweater is divided into: pure cotton, chemical fiber, wool, wool blend, cashmere.

1. Pure cotton wool is soft and warm, free from fuzz, shrinks and deforms when washed, the more it passes through, the elasticity is small, the color fastness is not strong, and it is easy to fade when washed at high temperature.(pure cotton sweater, no fuzz, but easy to deform, the warmth retention effect is average.)
2. The chemical fiber yarn does not shrink, feels smooth, and has high elasticity. It is best to smell it with your nose when you buy it. If there is no odor, you can buy it, otherwise it will hurt the skin. It is easy to generate static electricity, and the skin is dry and itchy when wearing. The price is cheaper than pure cotton.(Chemical fiber sweaters have good shape retention and bright colors. However, the thermal insulation effect is relatively poor, and there may be irritating odors. Smell them before purchasing.)
3. Wool blends are generally wool + acrylic or polyester or combed cotton, etc. This type of wool has better color fastness, better shape, little shrinkage, and a certain elasticity, but the warmth retention effect is not as good as that of pure wool. Pilling.(Wool blending has better thermal insulation effect, no shrinkage, no pilling, and moderate price. However, the thermal insulation effect is not as good as that of wool, so it is more suitable for southern wear.)
4. The wool yarn is soft, elastic, feels good, and has good warmth retention. Rub the sweater on the cotton shirt for about 5 minutes, and then quickly separate from each other. If there is no "pop" sound, it is a real sweater; if there is "Clap" sound, even with static sparks, is a chemical fiber fabric, is a fake sweater.(The shrinkage rate of wool clothing is relatively large, which is determined by the morphological structure of the fiber itself. Cashmere fiber is composed of scale layers and cortical layers. It is easy to cause fibers to collide and stick to each other during the wearing process, resulting in pilling. It becomes smaller when worn, and the pilling is more serious. It should not be exposed to the sun, and should be washed in cold water or dry clean.)
5. The texture of cashmere is very soft and warm, with good elasticity, and it feels very smooth. It has the characteristics of wool. But its shrinkage rate is not as high as that of wool.(Cashmere sweater, the fiber of cashmere is relatively short, so its pilling degree is not as serious as that of wool, but because the fiber filament is relatively short, there will be a layer of short hair exposed on the surface. The characteristics of cashmere and wool are similar.)