The term "illumination" comes from the illuminated manuscripts of the medieval period, before the printing press. A book, or a codex might be the more proper term, was made by scribes using a quill or reed to hand letter the words on parchment. An illuminator, somewhat akin to an illustrator of our time, would ornament the initial letters or margins of the text, using gold leaf for special books. Many of these books were for religious purposes: haggadahs, prayer books, scrolls of Esther, etc. There is a double entendre on the word illuminate, as it not only means to ornament with gold, but the illustrations can also comment on the text, bringing new light to the plain meaning. Rabbi Me'irah uses gold gouache paint, not gold leaf.