Custom Backpacks, Barton Recycled Sling Backpack - Recycled 600D, The Barton Sling Backpack has one single padded strap for an on-trend sling-style carry. This sling features a roomy zippered main compartment, front pocket with hook and loop closure and a side mesh water bottle pocket. The Barton sling backpack is crafted from recycled 600d polyester. ... #SM-6008 $8.58/each.