What is a characteristic of natural fibers like cotton and wool?

Natural fibers such as cotton and wool are derived from plant and animal sources respectively. A well-known characteristic of these fibers is that they are prone to wrinkles and shrinkage.

Cotton wrinkles easily because its cellulose chains bend and crease when the fabric is folded or compressed, especially in the presence of moisture and heat. When washed in hot water or dried at high temperatures, cotton fibers contract, causing shrinkage. Wool is similarly susceptible: its protein-based structure and scaly surface can cause felting and shrinkage when exposed to heat, agitation, or moisture changes.

The other options do not accurately describe natural fibers. Being highly durable and wrinkle-resistant describes synthetic fibers like polyester, which are engineered to resist creasing. Being synthetic and man-made is factually incorrect, as cotton comes from the cotton plant and wool comes from sheep. Being always expensive is not accurate either, as cotton is one of the most affordable and widely available fibers in the world.

Exam tip: When comparing natural and synthetic fibers, remember that natural fibers generally offer comfort and breathability but are more susceptible to wrinkling, shrinkage, and damage from moisture.