In the last few weeks we’ve been looking at painting processes and techniques so I reckon it’s time to get stuck into sculpture. Sculpture can be a taking-away process (subtractive) if using hard materials such as stone or wood or a building up process (additive) if using soft materials such as clay or wax. Marble is one of the traditional materials of sculpture in the Western canon I thought we’d start here.

Marble is rock that forms when limestone has re-crystallised. The tools used to carve it are the same now as always. These are the steps:

1. The sculptor roughs out the block with a hammer and pick. The weight of the blow is brought down on one point so bits of unwanted bulk burst away.

Michelangelo’s Awakening Slave is unfinished (it was intended for the tomb of Pope Julius II) which is brilliant for us because it shows the steps of carving. The rough areas around the torso show the pocked pick marks.

2. Next a tooth or claw chisel (shaped like a small comb) is used to model form and remove more stone. The areas of the Awakening Slave that look like they’ve had a fork dragged over them (the raised left arm, the beard, a little on the chest) have all been shaped by a claw chisel. Contours of a form are refined with strokes of a series of increasingly fine chisels.

3. A rasp (a row of little teeth cut into a piece of metal) is rubbed over the marble to emphasise shapes and eradicate chisel marks.

4. Fine chisels are used for detail.

5. A manual drill can be used to create holes for nostrils, pupils, etc. This is Bernini’s nymph Daphne screaming as she’s chased by Apollo. Hers is one of the most deeply-hollowed mouths in sculpture.

6. The final piece can be sanded to a matt or shined smooth finish using sandpaper or marble dust from the workshop floor. Check the extreme gleam on Michelangelo’s Pieta.

When looking at a marble sculpture it’s interesting to think about how the sculptor has made the most of the material and/ or been limited by it. A big bonus point is durability. Also, the white colour suggests purity and gives off a feel of the ideal.

In Three Forms (1935) Barbara Hepworth eradicates colour and focuses us on relationships in space, in size, in texture and weight.

Marble has a classical connotation and traditional association. Antonio Canova (1757-1822) was a leading light of Neoclassicism, a style influenced by archeological discoveries in Pompeii. He worked in mainly marble and modelled his style on classical examples. Here Canova carves Napoleon’s sister Paolina Borghese as a classical Venus.

Ironically Canova (and Renaissance artists) got it wrong: marble sculptures of ancient Greece and Rome were most likely painted with bright colours. Classical sculptures only come to us white because the paint has flaked off over time.

One of the best bits about working with marble is the fact that the surface responds to light. The surface of this 1st century BCE sculpture called Laocoön ripples into light and dips into shade pumping up the volume on the drama and intensity.

On the downside… Sometimes a marble sculpture can seem ‘contained’ by the restrictions of the original block. Take this Anavysos Kouros (c. 530 BCE) from the Greek Archaic period. This nude male was a warrior’s grave marker. His rigid stance (with arms that don’t leave his side) still suggests the shape of the block from which he was carved.

Another issue is marble’s limited tensile strength. It doesn’t support its own weight well. Dear Venus de Milo (c. 100 BCE) suffered.

Extended gestures must be limited and are vulnerable. In the case of the Rape of a Sabine (c.1582) by Flemish-born Mannerist sculptor Giambologna, the expressive spiral of figures with outstretched limbs works only because the group has its over the centre of gravity.

Sculpting is dirty, hard and physical work. Is it any wonder Michelangelo was built like a be-muscled bull (check out Raphael’s portrait of him in the School of Athens):

But despite the graft, the supreme masters of marble make it look easy. Like the High Baroque master Gian Lorenzo Bernini (1598-1680) who somehow managed to turn cold hard stone into palpable, squash-able flesh.