A moving item may be treated using a treatment member. Data may be obtained that includes a width of the moving item, a maximum speed of movement for a treatment member across the moving item to provide a required level of treatment, a speed of movement of the moving item, and a length of the moving item. An extent of movement of the treatment member across the moving item in each reciprocal movement of the treatment member and a speed of reciprocal movement of the treatment member across the moving item may be calculated based at least on the data to provide a required level of treatment across the moving item. The treatment member is reciprocally moved in a required pattern across the moving item based at least on the calculated extent of movement and the calculated speed of movement to provide a full treatment coverage of the moving item.