An article of apparel includes a composite material. The composite material includes a pliable first layer and a resilient second layer, where the first and second layers are secured to each other via a patterned strand network. In forming the composite material, the second layer is stretched and maintained under tension while the first layer is secured to the second layer via the patterned strand network. The tension on the second layer is then released, resulting in contraction of the second layer in relation to the first layer and an outward buckling or protrusion of the first layer in relation to the second layer to form protruding cells along the composite material that are bounded by portions of the patterned strand network. The patterned strand network can be formed using embroidery with one or more auxetic patterns in the stitching.