Mandala Crafts Bonded Nylon Thread for Sewing Leather, Upholstery, Jeans and Weaving Hair; Heavy-Duty (T135#138 420D/3, Black) - Walmart.com
Amazon.com: FIVEIZERO Extra Strong Upholstery Thread(1000 Meters) Bonded Nylon Thread,32 Pcs Heavy Duty Hand Sewing Needles Set for Home Upholstery Repair