97% cotton 3% spandex will sometimes shrink although usually not by much as the spandex material helps reduce the shrinkage.
Still if you use enough heat then the 97% cotton 3% cotton can shrink.
If you want to shrink your 97% cotton 3% spandex you can do so by doing the following.
Wash, dry, and repeat. This shrinking process is most effective with cotton, denim, and synthetic fabrics like polyester and spandex.
Next, tumble dry using your dryer's highest heat setting, and with the longest cycle available.
Boil in water.
Use a garment steamer.
100 cotton can go in the dryer but it should be tumble dried on the low heat or no heat setting and if tumble drying the 100 percent cotton on the low heat setting you should check it after 5 minutes to 10 minutes to make sure it's not shrinking.
To dry cotton without shrinking it the cotton should be dried on the low heat setting or air fluff setting which has no heat.
It's always best to use no heat when drying cotton to avoid shrinkage but if you use low heat you should check the cotton in the dryer after 10 minutes or so to keep it from shrinking.
You could also dry the cotton on low heat for 5 minutes or so and then dry the cotton the rest of the way on the air fluff or no heat setting.
You can spin dry cotton although you should use the air fluff or no heat or low heat setting to dry cotton.
High heat in the dryer can shrink cotton.
You only need one wash before cotton stops shrinking in most cases as most cotton only shrinks once and the fibers continue tightening if you keep washing them in hot water and tumble drying on high heat.
Most of the shrinkage and contracting of cotton will happen on the first laundry cycle of the wash.
Cold water does not shrink cotton so when washing cotton and to avoid shrinkage of the cotton you should wash the cotton on the cold setting and also use the air fluff setting to dry the cotton without heat.
Hot water and heat from a dryer can shrink the cotton.
100% cotton will shrink on low heat if dried for too long.
When drying 100% cotton you should dry it on the delicate setting or the air fluff setting and check it after 10 minutes or so to avoid shrinkage.
It's normal for clothes made out of 100 percent cotton to shrink, especially if the clothes have not already been pre shrunk.
Pre shrunk cotton usually only shrinks around 2 to 5 percent and non pre shunk cotton can shrink 20 percent if you're not careful.
The temp that 100% cotton shrinks is at 60 degrees although 100% cotton shrinks more at 90 degrees.
To prevent cotton from shrinking in the dryer you should use the low heat setting or air fluff setting or delicate setting on the dryer and wash the cotton in water temperature lower than 60 degrees.
Air fluff does not shrink clothes as air fluff spins the clothes without any use of heat.
And the delicate setting uses a small amount of warm air to help dry the clothing but air fluff uses no heat so the clothes won't shrink.
Both delicate and air fluff settings eliminate shrinkage of clothing.
Air fluff on a dryer means that the dryer drum rotates and ambient air is circulated through the dryer drum without turning the heating element on.
No heating element is turned on when using the air fluff setting on your dryer and instead room temperature or normal air temperature is used to dry your laundry.
This means that cold air will gently move through the fabric and allow them to relax and release wrinkles without applying any heat.
The air fluff cycle on your dryer can be very efficient on delicate clothes.
The air fluff dryer cycle uses no heat (as you can guess with its name) and no intense spinning.
With light air and smooth shifting, clothes float around until they become dry.
Air drying or air fluffing helps to remove dust and fluff up your garments when they've lost their volume from hanging in the closet or lying folded in a drawer.
Since the dryer doesn't produce any heat for this setting, you should use it for items that are already dry.
The two settings on a dryer that eliminate shrinkage are delicate and air fluff.
The delicate setting on the dryer uses a very small amount of warm air to help dry your clothing, and air fluff spins clothes without any use of heat.
Delicates: Low heat, so drying time will be longer.
It is best to use this setting to use for delicate fabrics.
Permanent Press: Medium heat while drying and is best used for colored fabrics.
Air Fluff: Not used for drying.
Avoiding heavy duty cycles, fast spins and high-heat drying can also prevent shrinkage.
Use delicate cycles instead, and place delicate clothes in a mesh laundry bag for added protection.
When drying, consider a low-heat or air dry setting.
When in doubt, always follow the instructions on your garment's care tag.