Black Card Stock: Pasteboard Coated with Lampblack

Black card shows up a pale deposit that would vanish on white card. Lampblack, the soot of oil lamps, is a deep black pigment because it reflects almost no light. Grind it into a thin warm glue size, brush two even coats on pasteboard, and press the cards flat as they dry. The picture: our diagram, the same pale deposit on white card and on black card.