Yarn is generally lighter than wood. This is due to the density difference between the two materials. Yarn is typically made from fibers, such as cotton, wool, or synthetic materials, which have a lower density compared to wood, which is composed of dense, cellular structures. For instance, the density of cotton yarn can range from 0.8 to 1.5 grams per cubic centimeter, whereas the density of wood varies but is generally around 0.6 to 0.8 grams per cubic centimeter. This means that a given volume of yarn will weigh less than the same volume of wood. Additionally, yarn is often used in thin, continuous forms, whereas wood is typically used in solid, larger pieces, further contributing to the weight difference.