Finding an affinity with French and Italian painting during his travels around Europe in the late 1950s, Brooker made a stark change to this international style; from nudes indebted to Sickert and English anecdotal Impressionism, he began to paint these austere still life paintings with nods to the architectural constructs of his fellow London Group artists, such as Coldstream or Pasmore, to give an expression is all his own. His mature paintings are noted for their cool simplicity, tonal stillness and strong compositions, very much painter’s paintings. A subtle depth of colour – what appears to be near-monochromatic whiteness reveals blues and fresh tan – and profound understanding of form elevate his subject to create a work that is minimal yet utterly engaging.

Writing in the preface to the Artist's important 1968 solo exhibition at Arthur Tooth and Sons, Edwin Mullins commented:
'suddenly formal compositions replaced genre, objects replaced people, an interior became a kind of laboratory, a cell, rather than a place to live in. Then there is the rich fuzz of paint which drags light gently into shadow across the surface of the canvas, picking up as it goes all sorts of echoes (after images) of those still-life objects clustered on the table below. Bottles, pots, jars, boxes, they have half-lost their identity until after a while the shadows between and around them become more positive shapes than they. Brooker's still-lifes acquire the anonymity of objects stared at so hard they shed their meaning, except the meaning they bestow on the space around them.'
(Edwin Mullins, ‘William Brooker, Paintings 1952-1968’, Arthur Tooth & Sons, London, 6-24 February 1968, p.1)