Using these Casey Cotton flat sheets is easy. Just put them on your king - size bed as you would with any other sheet. For the best results, make sure the mattress is clean and dry before laying the sheet. When it comes to washing, use a gentle cycle with mild detergent in warm water. Avoid using bleach as it can damage the fabric. You can tumble dry on a low - heat setting. To keep them looking and feeling great, iron on a low - medium heat if needed. And don't forget to store them in a cool, dry place when not in use.