Essays on Sculpture

• From the Latin, Cooked Earth.
• Formed by the disintegration & de-composed Igneous and Metamorphic rock.
• Either Residual (unmoved) or Sedimentary (transported).
• A colloidal lusterless substance that absorbers water and is then plastic and flexible.
• Durable when heated about 1100'F.
• Rich in Feldspar in the form of crystaline grains.
• Contains Iron oxide and Sulfur as fluxes and colorants.
• Terracotta is vitreous (5 and 15%) usually fired to cone 04 (1943'F).
• Sintering takes place when the mineral particles become fused during heating.
• Withstands deformation while retaining shape after pressure is released.
• Mainly Hydrated Aluminium Silicate, called Kaolinite.
• Has a regular structure of flat, shinglelike shapes.
• The particles tend to slide together and therefore give support to one another.
• Particle size 0.7 microns in diameter and 0.05 microns thick.
• The water content lubricates the plates allowing them glide over each other, this         actions gives the clay plasticity.
• Clay remains plastic as long as it is sufficiently wet.
• As the water evaporates the particles are drawn closer together, the clay becoming harder by stages.
• Different techniques are possible at different stages; from liquid (slip pouring) to dry (ram pressed) sgraffito.
• Has porosity and is brittle after firing.
• Breakage releases tension in the terracotta, causing the material to expand, making it impossible to replace the particles in their original position.
• Capable of being pressed into shapes and molds, it remains plastic enough to allow for changes and/or finishing.
• It has no intrinsic shape discernible by the naked eye.
• Takes any form within its structural capacity.
• Inert and permeant to a reasonable degree.

Writing