Laver is black and purple, and seaweed is green (dark green is best). Fresh seaweed (green) turns black and purple after drying. Only striped seaweed can be made into sushi seaweed after processing. Purple seaweed is processed once, and after secondary processing it becomes sushi seaweed (used for rice wrapping in Japan and Korea). In the picture below, the first seaweed on the left is, the second and third are low-quality seaweed, and the fourth is high-quality seaweed. < /p>