100% Sunbrella® Acrylic. Echo dune (57007-0000) is a light tan fabric that features a slub yarn for linen-like texture. It will hold its quality for years to come, thanks to the long-lasting durability of Sunbrella fabrics. It is resistant to stains, pilling, and abrasion, making it a great fit for many applications including indoor and outdoor upholstery, pillows, curtains, boat upholstery, and more.