Terracotta: The Intrinsic Qualities

  • 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.
Orange 11 Orange 11 Orange 11
Orange 11 Orange 11 Orange 11
Orange 11 Orange 11 Orange 11



Sculpture and Paper WordWorks


Sculptural Boundaries

Orange 11

Each Section: 15" x 8" x 22"
February & March 2002

Stephen Dubov
2202 North Loop #245
Austin, Texas 78756
(512) 206-4064