Encapsulated spring for cushion

A piece of furniture comprising:

• a structure having side walls with a first distance in-between two of the side walls, and top walls adjoining the side walls;
• and
• a blade assembly to cover at least partially the structure, the blade assembly comprising:
• an envelope comprising a support portion and side panels, the support portion comprising a top layer having the side panels extending therefrom, a bottom layer, and longitudinal sleeves extending between the top layer and the bottom layer from about a first one of the side panels to about a second one of the side panels, wherein the sleeves have a first length substantially equal to the first distance, the sleeves have an opening, with the longitudinal sleeves being isolated from each other;
• and
• blades of about the first length, the blades being inserted in the longitudinal sleeves through the opening;
• wherein the blade assembly is mounted to the structure with the bottom layer adjoining the top walls of the structure and the side panels extending over and being secured to the two side walls extending non-parallel to the bottom layer of the structure, with the side panels extending from the top layer non-parallel to the bottom layer closing the openings and thus preventing the blades from exiting the sleeves thereafter, and
• wherein the side panels of the blade assembly are secured to the side walls of the structure with the side panels maintaining the bottom layer abutting the top walls.