lol, that's a bit small. I don't usually go below a 1mm wall thicknell, though I think I have a 0.25mm nozzle somewhere which is somewhat finer than the 0.4mm that I usually print with.
Are you just getting the overall shape, or have you managed overlapping planks? I haven't tried, drawing something that looks like planks would be hard but pretty nifty if you can manage it