Putting it in the dryer for 25 minutes with other garments will shrink the sweater down 1 size. Look in the mirror at all angles to see if the sweater fits well. Observe if it feels too tight or is still a little loose where you want it to be form-fitting.
Washing fabrics, such as cotton, linen or wool, too vigorously can cause the fibers to tighten together and yield a shrunken garment. Hot water washing cycles and high-heat dryer settings can also damage the fabric and cause shrinkage. Learn more about washing wool or knit sweaters.
It's absolutely normal for clothes made from 100% cotton to shrink, especially if they haven't been pre-shrunk. Pre-shrunk cotton will generally only shrink 2-5%. Non pre-shrunk cotton, on the other hand, can shrink as much 20% if you're not careful. This is only true for 100% cotton, however.
Using heat in the wash and dry cycle allows new and possibly unwashed cotton to be shrunken down to a desired size. When washing new cotton sweaters, it is important to turn them inside-out and use a hot water cycle. Use bleach-free detergent to preserve the colors of the garments.
Whether your clothing is crafted from 100% cotton or a premium cotton blend, you should know that any clothing that contains cotton can shrink when subjected to high heat. To prevent shrinking, you should use appropriate protocols, i.e., cold water, delicate wash cycles, and low dryer settings.
There's Only So Much That Cotton Can Shrink.
You'll most likely shrink your clothing between 1 and 3 percent, or up to two sizes. That means a dress that's 35 inches long can lose up to one inch in length.
Fill the kitchen or bathroom sink with cool water and two tablespoons of fabric softener or hair conditioner. Submerge the sweater and let it soak for 10 to 20 minutes. Drain the soapy water from the sink, but don't rinse the sweater. Gently press the sweater against the sides of the basin to squeeze water out.
For example, both cotton shirts and denim jeans will shrink more in a warm or hot wash, followed by a high heat drying cycle. Steam heat will effectively shrink wool clothes, and some fabrics will even shrink when soaked for long periods in warm water.
I've seen some absolutely huge wool sweaters shrink down to infant-sized with a single hot water wash. Cotton is fairly easy to shrink down about 20% as well. Synthetic fibers are probably the hardest to shrink.
And the final insult can come if they are tossed in a hot dryer. The heat can cause natural and human-made fibers to shrink or stretch and increase pilling. Returning a synthetic fiber sweater to its original shape is impossible, but some natural fiber sweaters can be saved so they can be worn again.
Hot water causes the fibers in fabric to contract, which is what makes your jumper shrink. Check the manual that came with your washing machine if you aren't sure what the different temperature options are. You want water that's between 130 and 178 °F (54 and 81 °C). This method works for any fabric except wool.
Van Amber also says you can try to unshrink things using a steamer or an ironing board but, unfortunately, it won't be permanent. “The amount that you stretch it will remain until you wash it again, when it will probably shrink back.” But she says you may have some luck with wool – as long as it hasn't been felted.
A sweater should fit tight enough to complement your body, but not too tight where it looks suffocating. Your preferred fit will also vary based on the type of sweater you're wearing. This is due to the difference in material, style, and occasion.
There is nothing wrong with getting your sweater just a little bigger than what you are usually measured for. If you take care of your sweater, and avoid exposing it to extreme conditions (especially heat), your sweater should retain its shape for the most part.
Regardless of the type of garment—shirts, cotton, hoodies, and pants/jeans—or fabric, from rayon to 100 percent cotton, the most common process for potentially shrinking clothes is to machine wash them with hot water and machine dry them with high heat.
Unfortunately, certain fibers can shrink and weaken in hot (above 130 degrees Fahrenheit) water, but won't get a deep, thorough cleaning in anything considered too cold (between 60 to 80 degrees).
Wool shrinks at different rates, typically between 20-50%. In order to get an accurate shrinkage rate, it's a good idea to make a sample with the wool you intend to use for your final felting project.
The heat and action in the washing machine can cause wool to shrink. Wool fibers are made out of protein scales. Heat and motion cause the scales to grow and rub against one another, which draws the fibres closer together. The wool shrinks more as the fibres get closer together.
Wool fiber swells when it becomes wet and then contracts when it dries. This is what causes wool to shrink when you wash it in hot water. So If you don't want it to shrink, just avoid washing it in really hot water. Handwashing in cool or slightly warm water is always recommended for wool garments.
No matter whether they're cotton, wool, linen or silk — cotton shrinks the most, silk the least — a combination of heat and water will always do the trick. Most shirts will only shrink 20 percent max, though — so a size or two. Don't expect to turn an XL into a Medium or a Large into an XS.