sculpture

subtractive scultping methods

carving (eg. wood, stone, ivory)

additive sculpting methods

casting (bronze, metals, wax plaster), modeling (clay, plaster, wax etc), assembling (mixed materials)

stone carving marble

Most important stone. Usually polychrome, until the renaissance. marble is a metamorphosed form of limestone, can be colored during this proces with pigments.

marble in ancient greece

Parian marble (from Paros), or Pentelic marble (from mount Pentelikon)

marble in post-classical Europe

Carrara marble (from the Apuan Alps), carrara quarries were opened by the Romans, reopened in the 12th century. Marble does not naturally occur in Brittain, France or the Netherlands, so they had to import from Italy

stone carving tools

claw tool (sketching/hatching), flat chisel (removes high points), rasp tool (like a file), pumice stone (final buffing). Also used are drills and hammers

stone carving limestone

most common stone for carving in Europe. Weathers very well. Homogenus and inert. A sedimentary stone (not re-crystalized). Best worked in solid masses

stone carving, porphyry

extremely hard stone, can only be worked with emery or hardened steel. Hardness enables a very fine polish. Typical red color. Highly appreciated in roman times. Very rare and valuable

Terracotta

sculptures made by clay. After extraction clay must be pressed, washed and allowed to clear (with added minerals if necessary), until it has the right consistency. Can also be shaped in molds. After sculpture is dry it’s fired at 750-950 degrees

glazed terracotta

also known as maoilica. Originally used for utilitarian objects like tiles. After the clay has been fired a stannite glaze (silica, calcined soda-ash, lead, tin and metal oxides) is mixed with water and egg white and applied. the artifact is then fired again

bronze casting

bronze is an alloy of copper and tin (5-10%) with a melting point of 950. Can be mixed with other metals. Used to be valued and expensive. A foundry is needed, requires skills of other craftsmen

lost wax technique, steps

1) model carved in wood (postitive of the sculpture)
2) mould made in silicone (negative)
3) mould filled with melted wax (hollow positive)
4) finishing details on wax model
5) wax sprues are applied (channels for metal and ventilation) and a cup/funnel
6) model immersed in ceramic shell mould material (stucco, dry silica)
7) shellmould gets heated, wax is melted
8) shell heated, filled with liquid bronze
9) ceramic shell removed mechanically
10) sprues and cup cut off
11) metalchasing to remove undesired traces from casting
12) patinating to achieve desired shine & colour

patination

surface finishing or refinement in which the natural oxidation process is anticipated. Artificial patination prevents corrosion. Chemical reactions are caused on the surface which can change colours

modelers

the ones who work in plaster/wax, adding or taking away materials

sculptors

the ones who only take away materials and bring to life the hidden human figure in the marble block

modeling in stone carving

Used in ancient greece, development of the pointing machine. Making a reference in a clay, wax or plaster to be used as reference

pointing machine

enables making an exact copy of the (clay, plaster, wax) model in stone. Artists measures the model with the pointing tool. Then transposes proportions and depths onto the marble block with the help of a drill