But I can produce something that's vaguely pleasing on the iPad. It's taken a while for really good drawing apps to appear - the iPad, with its capacitive screen, isn't an ideal device for accurate rendering of a brush stroke - but there are now more than a few that do an amazing job. Critically, Autodesk's Sketchbook Pro allows you to zoom in to pixel level for fine detail - a capability that many other drawing apps lack.
And its Sketchbook Pro that I've been playing around with in the last couple of days, when I've been able to wrest the iPad from Abby, who's also fallen in love with it. A serious tool, with much the same capability as its desktop equivalent, but tuned for multi-touch gestures. Infinitely-editable pens, variable-opacity, blendable layers and a phenomenally customisable interface... it's quite extraordinary. And the full version costs... £2.99.