Cushioning articles such as mattresses can include a three dimensional wave spring core. The wave spring includes a polymeric lattice spring structure including a plurality of alternating layers stackedly arranged to define a height of the wave spring, wherein each one of the alternating layers is defined by a single strand having one or more upward and downward undulations, wherein the alternating layers are arranged such that an upward undulation of one layer is connected to a downward undulation of the other layer to define a cell configured to receive a compressive force, wherein the lattice structure has a sinusoidal shape when viewed top down and is configured to have three dimensional structure.