Twenty years I've been finishing things. Adding the last highlight, going back into the shadow, "one more pass." Today I stood at the easel with a small still life, a grey jug on ochre cloth, morning light coming in sideways, and at forty minutes it was right. Not perfect. Right. So I cleaned the brushes and walked away.

That has never once been my instinct. My instinct is to keep going until it's dead and then call it finished.

The old man who trained me used to say you must be able to see the moment the painting arrives, and then have the nerve to leave it alone. I nodded at that for years and did the opposite. There's still a part of me tonight convinced I've left it half done, that tomorrow I'll look and see the cheat.

Maybe I will. But the thing on the canvas right now has air in it, and I don't think I could have got that by working another hour.