I have six canvases stretched on bars I built in 2009, in my old studio on the third floor, before I knew what I was doing with a mitre saw. The corners are slightly off, I remember measuring twice and still cutting wrong. Every few years I look at them and think, I should restretch these. And then I don't, because the paintings on them are done and the slight tilt gives them something. A small imperfection you can't quite name.

I told a young painter last week that he'd save himself time learning the joinery properly. Then I came home and looked at those bars. Naja. There's a difference between sloppy and accidental, and I'd rather be wrong on the accidental side.