Carmine red ink

The very expensive red ink was the carmine from the lice of the jimson weed.

Carmine is an organic red dye. It consists of calcium and aluminum salts of carminic acid. The term is derived from the Arabic-Persian word kermes for scarlet berry. The terms carmoisine, carmine red, cochineal (cochineal) are also commonly used. The color varnish is also known as Florentine varnish, ball varnish, Munich varnish, Parisian varnish or Viennese varnish. The shade obtained with this dye is also called scarlet.
In Europe, the dye mixture was obtained under the name Kermes from the Kermes scale insects (Coccus ilicis or Kermes vermilio PLANCHON) that live on Kermes oaks (Quercus coccifera L.), the Polish Kermes louse (Porphyrophora polonica L.) or the Armenian Kermes louse (Porphyrophora hameli BRANDT) that occurs on the roots of certain grasses.

Cheaper was the ink made from folium rubeum (red-brown folium) and wood ash mixed with urine.
A simple ink was the juice of beet. For this purpose, the beet was boiled, pounded to a pulp, the juice strained, filtered several times and thickened by boiling down and adding egg white.