When a picture is chiefly composed of light and half-light, the darks will have more force and point, but without the help of strong color to give it solidity it will be apt to look feeble, and when a picture is composed mainly of dark and half-dark the lights will be more brilliant; but they will be apt to look spotty for want of half-light to spread and connect them, and the piece be in [Pg 90] danger of becoming black and heavy.
— from Crayon Portraiture Complete Instructions for Making Crayon Portraits on Crayon Paper and on Platinum, Silver and Bromide Enlargements by Jerome A. Barhydt