Whenever I have been to the Joan Miró Foundation in Barcelona – and I have visited Josep Lluís Sert's lovely building on Montjuïc many times over the last quarter-century – I try to see Miró's great 1968 triptych Painting on White Background for the Cell of a Recluse. It isn't always on display. There's nothing much to the three white canvases. No colour, no forms. Each enormous canvas is painted with a single black line over an unevenly primed white ground. You can tell where the slender brush has run out of paint, is recharged, then continues on its way with the same unknowable purpose, like the passage of an ant or a bird in flight, or the journey the eye makes along a horizon. Or like a long hair lost in the bedsheets, a memory of something or someone.
The recluse of the title might be the artist himself, painting one afternoon with the shutters closed against the brightness of the day in his studio on the island of Mallorca, during the month that the students rioted in Paris and General Franco still ruled Spain. It is a daft idea, to paint just a skinny wandering line across such a big canvas. How could it possibly work? But it does. There is a palpable difference between a line that's alive and tense and somehow natural, and one that dies like a bum note. You can feel the vitality of Miró's line from your head to your toes, your hand clenching and unclenching in your pocket, somehow feeling in your own body the artist's concentration – the tensing of his wrist, the movement of his hand – as you follow the line on its way to nowhere. I imagine Miró holding his breath as he draws, and I hold mine too as I look.
This work, along with three other late, large triptychs, is now being shown in two beautifully installed octagonal rooms towards the end of a new retrospective at Tate Modern. Joan Miró: The Ladder of Escape brings us his art not just in its most characteristic guises – playful, childlike, direct – but attempts to bring out Miró the "international Catalan" and internal exile in Franco's Spain; Miró the political artist; and the avant-garde surrealist and modernist who wanted – so he once said – to assassinate painting.
