He furiously scribbles them in pencil at the margins of his pictures and in patches of unpainted canvas that he allows to interrupt images of bright swirling patterns.

The pin-stripe effect was achieved by painting parallel, evenly spaced, black enamel stripes separated by narrow strips of unpainted canvas.

For some time now, stretcher bars and unpainted canvas have jostled for attention, but in the new paintings these elements are fully integrated; at times you'll hardly know you're looking at them.

On closer inspection, the imagery breaks down into graphic, paint-by-numbers-like abstraction, with forms busily defined by thin grooves of unpainted canvas.

Sky fills the spaces between bits of unpainted canvas, the spaces, as if in ghostly recession, becoming branches of the tree.

Chunks of unpainted canvas suggest bleached rocks or walls punctuating the terrain, while slivers of cobalt blue look like skeletal shadows and hints of water in an otherwise parched environment.

This new aesthetic found expression in a series of paintings, the Black Paintings (69) in which regular bands of black paint were separated by very thin pinstripes of unpainted canvas.

This mosaic of lavender, pink and yellow touches, separated by stretches of unpainted canvas, illustrates the truth of his remark.

Brushstrokes are broad and distinct from one another, sometimes with areas of unpainted canvas showing through.

There are rarities, too, like unpainted canvases or unused boxed sets, and there are paintings that remain rumors.