Using these Casey Cotton sheet sets is a breeze. Just put the fitted sheet on your super king 40cm bed, making sure to use the tags to get the correct orientation. Then, lay the flat sheet over the bed and tuck it in neatly. You can add the pillowcases to your pillows for a complete look. When it comes to washing, use a gentle cycle with mild detergent. Wash them in warm water, but avoid using bleach as it can damage the cotton. After washing, tumble dry on a low - heat setting to keep the fabric soft and maintain its shape. Don't iron on high heat; a medium - low setting is best to avoid scorching the sheets. With proper care, these sheets will last you a long time and keep providing you with a comfortable sleep.