What is a potential disadvantage of wet cleaning natural fibers?

Wet cleaning natural fibers can lead to shrinkage, which is a significant concern when dealing with materials such as wool, cotton, and silk. Natural fibers have varying levels of moisture absorption, and when they are subjected to water, the fibers can swell, causing the fabric to alter in size. This is particularly true if the cleaning process fails to incorporate the proper techniques, such as maintaining appropriate water temperature or using a suitable detergent.

In contrast, while some of the other options may present challenges in certain situations, they do not directly relate to the inherent properties of natural fibers like shrinkage does. For example, while the cleaning process may be time-consuming, this is not an exclusive disadvantage of wet cleaning natural fibers. Similarly, special equipment is often necessary for various cleaning methods, but it does not generally pertain strictly to wet cleaning. Additionally, effectiveness on dark fabrics is not inherently linked to the wet cleaning process itself, as it can be influenced by other factors, such as dye stability and cleaning solution composition.

Overall, shrinkage is a direct consequence of using water on natural fibers, making it a key consideration for upholstery and fabric cleaners.