Coasters That Work Wool is the most hydrophilic of all natural fibers absorbing as much as 30% of its weight without feeling wet. Their traditional Bierfilzl “Beer Felt” are the highest quality German Merino wool felt coasters on the market today. Their clean and minimal execution offers an unexpected textural and refined modern heritage element to any home decor. Set includes 6 hand-cut heavy duty 5mm thick mixed color Merino wool felt coasters to provide extra surface protection. Each beautiful coaster has a small logo on the underside as our mark of quality.