C First up. Whose bottom is this?

W Michelangelo's David. The most famous bottom ever in art history, I should imagine. I haven’t seen this one in the flesh, as it were. I’ve seen the one in the V&A which is a plaster cast, but it’s pretty good. It’s pretty big and fleshy, isn’t it? A big botty. Isn’t it really high up?

C It was made to be high up, but you can get pretty close to it now.

W Because he was made to be seen foreshortened, so the head is really big, and the feet are a bit too small. I imagine the bottom is just about perfect.

C His hands are massive.

W Well the danger – with drawing at least – is to always get the hands too small. I probably do it, but I'm aware that it's better to get hands a bit too big rather than too small. Because in general hands can look very weedy and sad little things if they're too small, whereas actually hands are quite chunky and that looks better.

C Someone who does good big fleshy hands – as well as bottoms – is Egon Schiele.

W Yes, well his hands are bony and red and kind of like bits of meat on bones aren't they? They’re so articulated. There's no fudging it and doing a crappy little hand and thinking ‘that’ll do’. Every tiny bit is really well seen. And other things as well.The amount of fat on the individual is a very key thing for drawing. For bottom shape obviously, but for absolutely everything. For necks too. I'm always doing portraits and the width you do someone's neck is so indicative of how large they are in general. If you give someone who's not fat a fat neck, they look fat. So I have to be aware not to. I'm always thinking not to do that with somebody who's skinny. If you give them an extra skinny neck, they immediately look like a skinny person.

W I slightly recognise this. Is it Leonardo?

C It is yes.

W Are they all going to be from around the same time?

C The 1500s was a golden age for bottoms.

W Well, absolutely. I’m not keen on this one actually. It’s more of a study in anatomy. So it's a bit boring. I think it’s just the upright flatness of it. It’s a problem in general, because there's always a temptation to make things too flat. So if I hold my hand out to you, you just see blobs on the end of a lump. It’s really difficult to draw that because your brain is always trying to tell you that a hand looks flat. So you're always lifting it up or flattening out or making things plain in front of you because you want everyone to know where you are in the drawing, what's happening. To draw the real strangeness of a body and all its angles is one of the tricks.

C Well that strangeness certainly comes out in some of your drawings of bottoms here.

W I hope so. I was once at life drawing and the the model was on a raised platform looking straight at me, so all I got was a knee and the top of the head. And I said to the person drawing next to me, God, this foreshortened view is awful, isn't it? And he and he said, No, they’re the most fun to do. And I suddenly thought, Yeah, of course they are. Why am I wanting an easy view or what I consider to be an easy view? You want a difficult, unusual, challenging view if you want to do an interesting drawing. So he flipped my brain. The other way round. So if you do see something like that, the great thing is to have a go at it and see if you can do something that in isolation looks completely weird and wrong, but actually is more like the reality of things.

C I guess your brain tries to fill in the gaps, and the trick is to draw what you’re seeing.

W Yes. If you were going to do a symbol of a hand, for a ‘do not touch’ sign in a museum or something like that, you wouldn’t do a foreshortened hand. But it’s no less a hand.

C They say that Egyptian wall paintings – that the reason they are shown with their bodies to the side like that – it’s because it’s more like a symbol. The most body-ish version of the body.

W Yes, well those Egyptian reliefs are some of the most beautiful, elegant, lovely things that have ever been done, ever. So all that stuff about funny angles instantly goes out the window. Because it’s something about the awkwardness that makes it.

W Picasso. He’s obviously the person that everyone goes to who's interested in figurative art and I always kind of think that all his very direct depictions of anguish and misery and torment quite often to me, they're just a bit too graphic to be visceral. He's got such a fantastic line, and his drawing is so amazing, and he’s so brilliant at creating flat areas and shapes and things that are all very beautifully simply stylised. So it doesn't really have a visceral punch to me. This one looks a bit like a sort of floppy insect.

C It’s more frantic than visceral really.

W It’s also in a rather elegant domestic interior to a degree, which is interesting.

C How much do you think about the interior you’re painting in?

W Not enough. I’m trying to do oil painting now. To make actual pictures. Some of these ones have a suggestion of an environment, and that can be important for an atmosphere.

C And you wouldn’t tend to include an statement object? Like the red armchair.

W I always slightly dread it when people bring out props at life drawing, because they're usually some really awful tatty, scraggy plastic skull, or a horrible old toy that comes out every time, or really ugly chairs. So I've usually just focused on the figure.

C What about the man in the hat?

W Well that was at life drawing. And they had all these awful props. But they also had this hat which turned out to be quite good. And he was more of an actor performer. Which I think comes across.

C It does.