100 Core Spun Polyester All Purpose Thread, 40 wt.,600 yards per miniking spools ideal for modern and traditional machines. Stronger than standard spun polyester threads. Machine friendly and laundry safe. Ideal for upcycled fashion, bridal, craft, window treatments, home furnishings, table linens,pillows, construction sewing, outerwear, tote bags, quilting, and Sashiko sewing. For medium to heavyweight fabrics including canvas, denim, upholstery, linen, and corduroy. Made in the USA.