Cotton sweaters can be worn next to the skin, like shirts. After wearing a cotton sweater this way, some people want to wear cotton sweaters from September to May. However, using bleach to remove stains will almost always change the color of a cotton sweater.
Cotton sweaters can safely be machine washed, but since cotton absorbs huge amounts of water, they can stretch out of shape if machine dried. Cotton is a fairly stable fibre; it will normally stretch just a little when worn and shrink just a little when washed. To control the direction of shrinkage, spread a freshly washed cotton sweater flat on a lawn chair in front of an electric fan.
Cotton is often dyed in deep, even harsh colors so the colors can mellow with repeated washing. Most cotton will gradually fade back toward its original color over the years. (The original color is normally white, but may be tan, pink, or even green. Naturally tan or pink cottons hold their colors for a long time; naturally green cottons tend to fade to off-white.) To minimize fading, store cotton material away from direct sunlight.
Cotton is biodegradable; it will soften and fray over time. Some cotton fibre will form pills if rubbed vigorously in laundering. Using a “gentle” or “delicate” laundry setting may reduce fraying, but nothing will really make cotton as durable as acrylic.