Carrageenan each plant weighs approximately 1 kg. The "E. cottonii" variety has been reclassified as "Kappaphycus cottonii" by Maxwell Doty (1988), thereby introducing the genus "Kappaphycus", on the basis of the phycocolloids produced (namely kappa carrageenan). After harvest, the seaweed is dried, baled, and sent to the carrageenan manufacturer. There the seaweed is ground, sifted to remove impurities such as sand, and washed thoroughly. After treatment with hot alkali solution (e.g., 5–8% potassium hydroxide), the cellulose is removed from the carrageenan by centrifugation and filtration. The resulting carrageenan solution is then concentrated by evaporation. It is dried and ground to specification.
Tyrian purple this ability has sometimes also been historically exploited by local inhabitants in the areas where these snails occur (Some other predatory gastropods, such as some wentletraps in the family Epitoniidae, seem to also produce a similar substance, although this has not been studied or exploited commercially). The dog whelk" Nucella lapillus", from the North Atlantic, can also be used to produce red-purple and violet dyes. The Phoenicians also made an indigo dye, sometimes referred to as "royal blue" or "hyacinth purple", which was made from a closely related species of marine snail. The Phoenicians established an ancillary production facility on