Ink was also common in most countries. Red Ink, made of vermilion, cinnabar, or purple, is very frequently found in manuscripts; but none are found written entirely with ink of that color. The capital letters, in some, are made with a kind of varnish, which seems to be composed of vermilion and gum. Green Ink was rarely used in charters, but often in Latin manuscripts, especially in those of the latter ages. The guardians of the Greek emperors [or rather the Regents of the Empire] made use of it in their signatures, till the latter [the monarchs during minority] became of age. Blue or Yellow Ink was seldom used but in manuscripts.[!!!] The yellow has not been in use, as far as we can learn, for six hundred years.
"Metallic and other characters were sometimes burnished. Wax was used as a varnish by the Latins and Greeks, but much more by the latter, with whom it continued a long time. This covering or varnish was very frequent in the ninth century.
"Color. The color of Ink is of no great assistance in authenticating manuscripts and charters. There is in my library a long roll of parchments, at the head of which is a letter that was carried over the greatest part of England by two devout monks,
