One of the lots is a Jean Giraud cover for a 1970 Blueberry comic called the "Iron Horse," 36 X 49.2 cm (14.17 x 19.37 in.). Giraud's image of the American West evokes the work of Frederic Remington and Charles Marion Russell.
Giraud (1938-2012) is better known by the pseudonym Moebius, which he used for his science fiction work. He painted with equal virtuosity in almost every medium, including pen-and-ink, watercolor, colored inks, acrylic, and oil.
This one is in gouache. The detail shows the variety of strokes and colors he uses to describe the complex forms of the train. He probably executed a careful underdrawing first, but he didn't hesitate to cover it up with opaque paint.
Gouache allows for a variety of handling, from fine delicate strokes, such as those of the grasses in the foreground, juicy blobs, such as on the horse, or brilliant opaque color, such as in the sky.
The upcoming Christie's auction will include a fine selection of bandes dessinées and illustration, including Uderzo, Bilal, Manara, Pratt, Schuiten, Juillard, and Guarnido. The selection was made by Galerie Daniel Maghen of Paris.