Virgil Finlay (1914-1971) was a prolific science fiction and fantasy illustrator. He was a master of the scratchboard, which is a board coated with white clay and covered with black ink, which is painstakingly scraped off with a stylus. This technique is also called "working from black to white."
In 1935, when Finlay was 21 years old, he sent samples of his intricately stippled work to the publisher of Weird Tales, who was immediately taken with the young artist's spectacular otherworldly style. But he was unsure whether the detailed drawings would reproduce well on the cheap pulp used in Weird Tales. Fortunately, Finlay's illustrations survived the medium and he quickly became a favorite with readers.
(The original width of this image, a detail from a larger illustration, measures 1.25 inches)
The BPIP biography of Finlay describes his technique:
Once you've seen the detail, it's important to understand how he did it. A lot of artists use pebble board to simulate stippling. The textured surface of the board prevents the pencil from filling in the depths, making a seemingly random pattern of black dots. Finlay did occasionally use pebble board, but his preferred method of working was on the clay finish of scratchboard. Using an ultra-fine lithographic pen, he would dip just the tip into India ink and allow only the liquid ink, not the tip of the pen, to touch the surface. He then wiped the residual ink off the pen point and repeated the procedure for the next dot. This incredible and incredibly labor-intensive technique, coupled with his enormous talent, created images of near photographic quality - in the service of depicting the fantastic. No one else ever made the unknowable seem so immediate and real.
Finlay's popularity grew every year and he remained in high demand until the collapse of science fiction magazines in the 1960s. He turned his talents to astrology magazines, which published his work until his death in 1971. All told, he produced more than 2500 illustrations over the length of his career.