Fluid-filled cushioning article with seamless side walls and method of manufacturing

A method of manufacturing a cushioning article, the method comprising:

• wrapping a polymeric sheet around a support so that the polymeric sheet surrounds a perimeter of the support and a first portion of the polymeric sheet adjacent a first side edge of the polymeric sheet overlaps and is stacked on a second portion of the polymeric sheet adjacent a second side edge of the polymeric sheet;
• welding the first portion to the second portion at a first weld disposed between the first side edge and the second side edge while the polymeric sheet is wrapped around the support so that the polymeric sheet forms an open-ended sheath with a top wall, a bottom wall, a first side wall and a second side wall and with the first weld disposed at only one of the top wall and the bottom wall;
• removing the polymeric sheet from the support;
• and
• after removing the polymeric sheet from the support, welding the top wall to the bottom wall at a first transverse weld and a second transverse weld, both the first transverse weld and the second transverse weld crossing the first weld and extending from the first side wall to the second side wall so that the polymeric sheet defines and encloses an interior cavity capable of retaining a fluid, and the first side wall and the second side wall are weld-free.