Natural fibers like modal are known for their ultra soft textures, but washing on too harsh a cycle can cause lint pills to develop long term. If you're worried about long term longevity, separate lights from darks, and wash separately. You can machine wash in warm water, preferably on the delicates cycle, and don’t use bleach or fabric softener. Tumble dry on the lowest heat setting and remove as soon as they’re dry. During our lab tests with SGS, an independent testing service, we got virtually no shrinkage in their most rigorous hot washing test. However, we don't recommend this long-term.