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
Purple of the Emperor Justinian in Ravenna. The chemical composition of the dye from the murex is close to that of the dye from indigo, and indigo was sometimes used to make a counterfeit Tyrian purple, a crime which was severely punished. What seems to have mattered about Tyrian purple was not its color, but its luster, richness, its resistance to weather and light, and its high price. In modern times, Tyrian purple has been recreated, at great expense. When the German chemist, Paul Friedander, tried to recreate Tyrian purple in 2008, he needed twelve thousand mollusks to create 1.4 ounces