A tube of paint, in this case a tube of white tempera paint from Whistler’s studio (below). There are other whites in the artists’ palette: ‘Flake White’, as the name implies, not quite graspable in the hand; ‘Titanium White’, tougher and more opaque; ‘Permanent White’, don’t be fooled; yet a simple tube of ‘Zinc White’ paint says much about the nature of white itself.

As a colour white is furtive, there but never quite there, either too much or too little. Tainting easily, it is like ripe fruit, easily marked and bruised. White often shies away from its whiteness, preferring the shadows. In the tube it is this thing named white. Once squeezed out, its substance spread, dispersed into a mere surface, it becomes something else, the pristine feel of a dress, the delicacy that is lace, the glow of light. In the process it has gone from substance to intimation, attribute and atmosphere.

In his book Remarks on Colour, Ludwig Wittgenstein distinguishes between two kinds of colour: colour that sits on the surface of things, as paint sits on a surface, and colour which goes right through something, becoming inseparable from the thing itself, as orange is in the carrot. The painter works with the flat surface colour, yet paradoxically desires the other, seeks to give colour a full body so that its presence can body forth into the world. Making flat surface and paint so concrete and real that we believe in it, as being as present in the world as you or I.

“People are felt rather than seen after the first few moments”: perhaps this thought from John Steinbeck is also true in looking at paintings. We feel our way into paintings, looking simply the vehicle our feelings are carried on. In that sense ‘meaning’ in painting is skin deep. In Symphony in White, No.1: The White Girl, it is the engagement and pleasure of all the whites, on fabrics, surfaces and folds, lights and shades, which draw us into the painting. So let us briefly forget Joanna Hiffernan, ‘pictured’ in Symphony in White, No. 1: The White Girl. For the painting is no more a portrait in any deep psychological sense than are Goya’s full-length, piggy faced royals. The context gave Whistler, just as it gave Goya, the license, freedom, to paint, and paint he did, wallowing in the luxuriance of silks, satins and lace, the play of texture against texture, shape against shadow, form against line. The history of painting is a history of the painter’s resistance to the greedy grasp of presumed overt subject matter. Whistler tells us this concerning his portraits when he titles them Symphony in White, No. 1 or Harmony in Green and Gray, adding further details as an afterthought.

She leans into the light, towards the white. It is Georgia O’Keeffe, she is in New Mexico. It is the white of belladonna, in this case two jimson weeds; she has painted their petals enveloping pistil and stamen as if they were a pair of caring hands (Georgia O‘Keefe, Bella Donna, 1939). O’Keeffe got white as a colour. Many painters don’t and treat it as a gap, a gash or accent. The colour white can be as challenging for the painter as the blank white sheet of paper is for the writer.

I painted my first white painting in 1989, why I don’t know, perhaps the wider colour palette available to the painter just too much for me, was more than I could handle. Colour all too easily slips into decoration, and too many colours into fireworks. Since that first encounter white has stayed with me; I need to see it, feel it around me, stay close to the quiet it allows. A few years later I painted three large predominantly white paintings in homage to Marianne North, the intrepid 19th-century explorer and botanical painter (Marianne North No. 1, 1994-95; above).

On one of her trips in 1871 North visited Frederic Church, the American Luminist painter, at his ornate home in Olana, upstate New York. She recalls how Church had recently acquired two white asses from Damascus, which he was keen to show her. I try to think of American white – is it luminous, as are the paintings of Church himself? – but cannot fix it. That is, not in any broad sense, say, as in the way that Dutch white is strait-laced, Italian white of the Holy Ghost, or Spanish white knife-edge sharp. Rather like the dew of English white in Constable’s work which seems to fleck and fade away, American white’s emphasis on surface slips and slides, gives distance to the specifics of place.

Stepping into the bathroom, four white walls, all painted the same brilliant white, except not now. One, the one lit by the full glare of the sun, is luminescent; the wall to the right less bright, its white tinged by the green of the landscape outside.

Opposite, the wall half in shadow feels like a white relaxed, whilst the wall in which the window sits, in full shade, gives life to the others. The ceramic tiles of the shower modulate their white as if the colour were singing, whilst the shampoo, poured out, reacts like the colour of the albumen of a poaching egg as it turns from fluid to white form.

The rough and smooth sides of the towel give different whites, one withholding, whilst the smooth side spreads its white with pride. A porcelain hand basin holds its white slowly, and as water fills it goes from a certain white to white seen at a glance. Whilst the bar of soap shelters its white the same way a candle does, as if within it there is an inner light, a profound white, which with each washing, as the bar wears down, one will get closer to seeing and touch, but of course one never does. The toothpaste tube and its cap are two different whites, the cap a harder, cleaner white, the tube white softer and more greyed, showing something of its purpose to be squeezed to reveal the full refreshing white of paste.

On the windowsill a white orchid stands, its full petals set against the daylight. A single petal as white as perhaps any white can be, through which the light glows, is translucent with life, breathing light and white as one. And where one petal overlays another, a white so dense and rich is formed that one has to remind oneself that this colour is simply named white.