Care instructions vary from mask to mask, and you should consult the manufacturer’s guidelines to find out which apply to yours to keep it working properly for as long as possible. Some are fully machine washable, while others have machine-washable linings but require an inner to be removed first. Others must be hand-washed, while some should only be wiped clean. If you have a microwavable sleep mask, adhere to the maximum power and time guidelines. Often, only the inner pad or bag is microwavable. Remove the lining first to avoid melted buckles, warped elastic, or burnt fabric.