Paintings surprise me. I've just completed my latest, and although the idea was there for a while - I mean I lived the disaster and personal mortification, the way it finished, that was unexpected.

The layers are blocked in okay? So today was about tightening up lines, solidifying coverage of the paint, adding tweaks to expressions, and shades to hues; then I'm looking at the canvas, and before I know it I've swirled the brush here... then here and then here, here, here and here. I stop, stunned and look. I like it, so I add here, and here, and there. So now I understand what the painting needs, where it's going, so the palette is daubed and dabbed and scurried until I've added, tweaked and blitzed the original idea to produce the finished painting. It still has the structure of the sketch, but now the energy of the moment is back, is infecting the whole scene, and what I had in mind has gained something from the move from sketch to canvas - before was the cartoon, this is the finished article - assuming the cat doesn't knock it over today.

This element of chaos is important, it keeps ideas and designs alive, prevents you from becoming too complacent about an idea or a process. Recreating an idea is no longer simply about laboriously drawing a design onto the canvas, it is about finding a way for the paint to breath; to give the elements of pattern, expression, line, colour, pace and composition room to wriggle, to find their own equilibrium. When this happens the painting becomes unpredictable, but takes on a unity of determination to shout out and demand the viewer come into the world it has created.

These are moment when preparation and skill and analysis are give something more, when paint becomes a painting, when a sketch lifts itself from the page. These are moments that you hope for, that you fear you won't find when you begin the project. The spontaneity comes from the detail, but it is the inspiration that makes you feel in what you do.

Easy as falling over? I think not.