Alginates are derived from brown seaweed. These unique dressings are composed of soft, non-woven fibers shaped as ropes (twisted fibers) or pads (fibrous sheets). Alginates are absorbent and conform to the shape of a wound. When packed, an alginate interacts with wound exudate to form a soft gel that maintains a moist healing environment. An alginate dressing can absorb up to 20 times its weight.