If you want to be taken seriously as a contemporary painter, paint big. ‘Blotter’, the picture that won the 34-year-old Peter Doig the John Moores Painting Prize in 1993, was over 8ft x 7ft. The pictures in his current show at the Courtauld are so big that only 12 of them fit in the gallery space.

‘Blotter’ was a dreamlike image based on a photo of the artist’s brother standing on a frozen lake in Canada, where Doig spent most of his childhood. Its title referred partly to his technique of letting the paint soak into unprimed canvas, partly to the way a single figure is absorbed into a landscape. Close in mood to Friedrich and in treatment to Munch, it marked out the Edinburgh-born artist as a contemporary master of atmospheric painterly effects.

The works in this new show were painted before and after Doig’s recent move back to London from Trinidad, where he spent his early childhood and has been based for the past 20 years. Anyone anticipating ‘Blotter’-like immersion will be disappointed. Only in ‘Alpinist’ (2019-22) – a postmodern spin on the sublime with its lone skier in a Picasso harlequin suit – does he pull out all the old painterly stops in evoking the snowy slopes patterned with pines and the marbled, churning glacier at the skier’s feet. Elsewhere he scrimps on atmospheric effects as if resisting the temptation to be decorative, allowing the merest shimmer of phosphorescence in ‘Night Bathers’ (2011-19). His figures have expanded to compensate. His monumental ‘Bather’ (2019-23) looms over us, a homage to Cézanne’s homonymous painting in which the French master’s stocky figure has mysteriously body-swapped with a hunky Robert Mitchum from a vintage photograph. The painting left me cold, but the photo is a scorcher.

Doig’s work, he says, is about creating ‘painted spaces’ related to places he has lived. In the past, those faraway places – Canada and the Caribbean – lent themselves to the strange, uncanny realities he likes to confect. How will he fill these spaces in London? With its disconnected figures and off-kilter perspective his first London painting, ‘Canal’ (2023), is weirdly reminiscent of Carel Weight. Weight’s weirdness, though, was contained within a narrow compass; on a canvas this size the effect is lost. Lovers of paint owe Doig a big debt of gratitude for rescuing the medium from the conceptual doldrums and inspiring a new generation of representational painters. Still, I wish he’d succumb to the decorative temptation and put the space of the painting to work.

Alice Neel (1900-84), whose major retrospective has just opened at the Barbican, was another painter who swam against the tide. When abstraction ruled, she persisted in painting that most fuddy-duddy of figurative subjects, portraits: she had an itch to record humanity and nothing would stop her from scratching it. In a 60-year career she recorded the humanity around her in a vibrant style combining the expressionism of Soutine with the clarity of Beckmann. She began with her neighbours in Spanish Harlem before moving on to the beat poets, intellectuals, activists, artists and eccentrics of Greenwich Village. Her choice of subjects did not help her career, but after the two sons she had brought up as a single mother left home and she moved to the Upper West Side in the early 1960s she started attending gallery openings. She had always invited random people to sit: the two FBI agents who came to question her in 1955 about her Communist party membership had politely refused, but the art world figures she now began approaching accepted. Warhol even submitted to posing stripped to the waist, exposing the scar left by Valerie Solanas’s shooting and the surgical corset the injury had obliged him to wear.

Neel was funny. She entertained her sitters with stories and jokes that made them drop their guard, and then pounced; having suffered her own share of heartache, her emotional seismograph was sensitive to the slightest tremor. ‘You don’t look anxious but you are anxious,’ she told feminist art historian Linda Nochlin and her daughter Daisy in 1973, then painted them perched on a green settee like a pair of coiled springs. She painted male nudes with it all hanging out decades before Freud and pregnant women a generation before bumps became a fashion statement. Her only large self-portrait (see below), finished at the age of 80, shows a white-haired, bespectacled grandmère terrible seated in a stripy chair without a stitch on, brush in one hand, paint rag in the other. ‘All my life I wanted to do a nude self-portrait,’ she confessed.‘But I put it off till now when people would accuse me of insanity rather than vanity.’

Neel aimed to ‘catch life as it goes by, right hot off the griddle’, and in this blast of an exhibition the life is still warm.