Some gastropods are capable of producing a pigment, the purple dye, which has been widely used in the past to dye a lot of different materials, while some bivalves can produce byssus fibres used in the past to make a very fine tis-sue. Cephalopods, octopus, and cuttlefish produce, thanks to specialized glands, a black pigment which is released in cases of danger to confuse the aggressor and promotes their escape: for centuries, it was used as ink, but is also appreciated in cooking pasta and rice.
In the Classical Age, Phoenicians were certainly the first and probably unique historic producers of purple, while in the Middle Ages, the pigment used at the Court of Charlemagne, was probably extracted by Britons from Nucella lapillus, a common gastropod from the North Sea. Little by little, this dye fell into disuse and around the 16thcentury, the dye shops in Europe were no longer be able to continue the ancient processes developed by the Phoenicians and the use of pur-ple was lost forever.
Many bivalves, but overall, the Mediterranean Pinna nobilis, can produce silky filaments, the byssus, a set of keratin filaments which can be processed to realize rare and filmy tissues of a nice golden brown colour. For many centuries, the byssus tissues were a hallmark of command and power, and were reserved to no-blemen and important members of the Church in Rome.