Amon Amarth ‘Vikings Circular’ Backpatch 130.18 NOK Back Patch. Designed to fit on the back of a jacket This is a sew-on woven patch, made from cotton, with standard backing and an overlocked edge. Sorry, the product is out of stock. Share Information Reviews Back Patch. Designed to fit on the back of a jacket This is a sew-on woven patch, made from cotton, with standard backing and an overlocked edge.