Layers of industrial, wool felt are laminated either side of the plywood core.
Here's a bit of text from Yu-Hun Kim:
‘EWE’ is a charaterised stool, inspired by the contrasting textural feature of soft and hard felt. It is playful, warm, cozy and natural.
Industrial felt, made form soft wool fiber, can be cut to precise sizes and thicknesses.
By cutting the laminated felt to a clean edge the stool has the appearance of solid object, however it still retains the felts softness like fur.