Husqvarna Viking OPAL 690Q Adding piping AND an invisible zipper to cushions by Elaine Theriault May 31, 2024 by Elaine Theriault May 31, 2024 This is a detailed sewing tutorial on adding piping AND an invisible zipper to cushions. Elaine Theriault sews on the Husqvarna VIKING Opal 690Q. FacebookTwitterPinterestLinkedinRedditWhatsappTelegramEmail