Green Denim sewing thread Gutermann TKT 30 - 833 This high quality Guetermann A series sewing thread set in No./Tkt 30,50 and 80 are used for sewing Denims or thick fabrics. This strong thread has the ability to withstand chemical washes and for Stone wash its recommended to use TKT30 thread. Use No./TKT 30 for the needle and 50 in the bobbin while sewing.