Paper marbling Turkish and Persian, which literally means Frankish. Historic forms of marbling used both organic and inorganic pigments mixed with water for colors, and sizes were traditionally made from gum tragacanth ("Astragalus" spp.), gum karaya, guar gum, fenugreek ("Trigonella foenum-graecum"), fleabane, linseed, and psyllium. Since the late 19th century, a boiled extract of the carrageenan-rich alga known as Irish moss ("Chondrus crispus"), has been employed for sizing. Today, many marblers use powdered carrageenan extracted from various seaweeds. Another plant-derived mucilage is made from sodium alginate. In recent years, a synthetic size made from hydroxypropyl methylcellulose, a common ingredient in instant wallpaper
Red algae contain the sulfated polysaccharide carrageenan in the amorphous sections of their cell walls, although red algae from the genus Porphyra contain porphyran. They also produce a specific type of tannin called phlorotannins, but in lower amount than brown algae do. Complete genome sequences are only available for 6 species of red algae, including 4 published in 2013. One of the oldest fossils identified as a red alga is also the oldest fossil eukaryote that belongs to a specific modern taxon. "Bangiomorpha pubescens", a multicellular fossil from arctic Canada, strongly resembles the modern red alga "Bangia" despite occurring in rocks dating