There is enough silver ion treatment embedded in the material that should last at least 12 months, which means about 30 washing cycles, after which there will be a gradual decline in the antimicrobial properties. All the information around washing the material is included inside the bedding, on the care label. However the main advice is not to dry clean the silk bedding and wash it with 30 degrees celsius. We recommend using the mesh laundry bag for your pillowcase. For the long-lasting results, hand-washing your pillowcase would be the best option. Also don’t use laundry detergent which contains bleach. Rinse your bedding before first use!