PATTERN. Eucalyptus ~ After the Eucalyptus tree bark pattern MATERIALS. Cellulose Acetate DIM. 1.2'' Diameter Hypoallergenic Post - Stainless Steel Cellulose Acetate Material ~ Much stronger and more durable than an acrylic material. Cellulose acetate is less brittle and wont break as easily. A renewable resource ~ essentially made from a wood pulp. It is the same material used for high-end eyewear frames.