Children Backpack Sewing Project. This is a fun project that took me 7 hours non-stop to make. I’m very happy with the result. I used red polkadot cotton-linen fabric for the outer, interfacing 2mm 180 gr with adhesive one-side from cotton and polyester for batting, and creamy white polyester fabric for lining. I also used 0.6 mm black elastic to make ruffled-style for the front pocket. I used zig-zag stitched for that, which worked perfectly for this project.