Quentin Blake at Marlborough Fine Art

_{Quentin Blake, 'Insects VI', 2012. Etching, 36.5 x 31 cm} Marlborough Fine Art on Albemarle Street, off Piccadilly, celebrates the 80th birthday of Quentin Blake this month with an exhibition of works on paper from this year. I’ve never met anyone who doesn’t adore Blake’s idiosyncratic illustrations, their affection first blossoming while reading a Roald Dahl book as a child or to a child. But the Marlborough show presents another side of Blake’s output, not illustrations for books influenced by a writer’s words, but images straight from the artist’s singular imagination.

Anthropomorphized animals are common throughout, and most charming in the series of coloured etchings ‘Insects’. Here an ant-like figure – roughly draughted in Blake’s characteristically improvisational style – hands some jewel-like presents to his offspring. Another plods home as the sun sets, his body drooping, briefcase in hand, while a younger specimen enjoys the benefits of four tentacles by reading two books at a time.

_{Quentin Blake, 'Girls and Dogs 2', 2012. Lithograph. Edition of 35, 55 x 75.5 cm.} Two mono- and duo-tone series of etchings pose women with animals ambiguously. The atmosphere moves away from humour to one of mystery and, perhaps, violence; in Women with Dogs II, a canine looks threateningly towards a woman on her knees, who holds up a scroll of paper daubed in red, echoing the crimson colour dotted across the horizon. Pastel series ‘Sporting Women’ shows female silhouettes, filled in with a kaleidoscopic range of colours, which bound around in front of a bare landscape, while another, ‘Women in Water’, shows the heads of women emerging eerily from the deep.

_{Quentin Blake, 'Women in Water 4', 2012. Stabilo watercolour pastels on cartridge paper, 30 x 42 cm.} The artist’s drawing series ‘Characters in Search of a Story’ is even more enigmatic. Individuals and couples stare out from the paper, their positions inert and their expressions inscrutable, willing us to typecast them in a certain role depending on their looks. It is as if the illustrator Blake, without a brief to fulfill, is happy to let his cast of characters wait for our instructions instead.

• Quentin Blake is at Marlborough Fine Art until 11 January 2013

Sam Phillips is a London-based arts journalist and contributor to RA Magazine

• Royal Academy of Arts