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
Shades of purple halfway between violet and magenta and thus fits the artistic definition of purple. Using additive colors such as those on computer screens, it is possible to create a much brighter purple than with pigments where the mixing subtracts frequencies from the component primary colors. The equivalent color on a computer to the pigment color red-violet shown above would be this electric purple, i.e. the much brighter purple you can see reproduced on the screen of a computer. This color is pure purple conceived as computer artists conceive it, as the color on the color wheel halfway between color wheel violet