Carrageenan is that the carrageenan is first dissolved and filtered to remove cell wall debris. The carrageenan is then precipitated from the clear solution either by isopropanol or by potassium chloride. A hybrid technology in which seaweed is treated heterogeneously as in the semirefined process exists, but alcohol or high salt levels are used to inhibit dissolution. This process is often used on South American seaweeds and gives some of the cost benefits of semirefined processing, while allowing a wider range of seaweeds to be processed, however, the naturally low cellulose levels in some South American seaweeds allow them to be
Purple and silk, without the use of mordant. Cudbear was developed by Dr Cuthbert Gordon of Scotland: production began in 1758, The lichen is first boiled in a solution of ammonium carbonate. The mixture is then cooled and ammonia is added and the mixture is kept damp for 3–4 weeks. Then the lichen is dried and ground to powder. The manufacture details were carefully protected, with a ten-feet high wall being built around the manufacturing facility, and staff consisting of Highlanders sworn to secrecy. French purple was developed in France at about the same time. The lichen is extracted by urine