Air outdoors - preferably in damp weather. Spray with water and stretch by pulling up with pins - do not iron - if so lowest temperature from the backside with a moist cloth in between.
Gentle hand wash using a mild and gentle detergent or wool soap in clean, lukewarm water, approximately 30°C, Allow to soak for a period of 10 minutes before rinsing thoroughly firstly in lukewarm water, then finally in cold water.