Monarch Plank Boulevard Herringbone Collection Calvaire European Oak. Experience natural beauty of European Oak sourced from responsibly managed forests in Europe and the U.S., with use of the most eco-friendly adhesives and finishes available. Calvaire European Oak of Boulevard Herringbone collection features light wire-brushed texture and rustic grade with natural treatment of the wood. Dry-sawn 4 mm thick top layer. Calvaire comes with a lifetime structural warranty, a 25-yr residential finish warranty and a 3-yr light commercial warranty.