Andean Arts

CERAMIC TECHNIQUES

In order to make a ceramic vessel, one must first start with a paste that can be modeled, retain its shape as it dries, and then be fired to harden the clay.  For this process to be successful, a type of temper is mixed in the clay. Temper prevents the ceramic object from breaking during the firing process because it helps distribute the heat more evenly throughout the object.  It could be pieces of shell, ground up ceramic vessels (also known as grog), or sand, and it could be coarse or so fine that it is almost impossible to see at first. Many of the Andean ceramic vessels on display in art museums today are finewares made for burials, and these often have thin walls and use a very fine temper that is difficult to see.

Andean ceramics are hand built, using either coiling (making a long coil with the clay that forms the basic shape of the vessel) or pinching (using one’s fingers to model the shape out of a ball of clay) or a combination of both.  Stirrup spouts were probably made by rolling a flat piece of clay around a cylindrical object. Separate pieces can be “glued” together using a slip, or watered down clay, while the clay is still leather-hard.  Different colors of slip can also be applied before firing with a brush (the mineral oxides in the clays determine the colors).   Incised designs can be made by drawing on the leather-hard clay with a sharp tool.  The surface of the vessel can also be burnished by rubbing a smooth object, such as a pebble, on the clay; this results in a very smooth and shiny finish.

Just as there are different ways to model the vessels, there are also different ways to fire them.  Most of the vessels you will see here are fired in pit fires.  These are simple pits dug into the ground, with fires fueled by animal dung.  Within these pit fires, the firing atmosphere can be either oxidized or reduced. Oxidation involves the free flow of air (oxygen) through the fire.  In this case, the clay turns its natural color (in the case of iron-rich clays, the vessels would turn red).  Reduction firing, on the other hand, involves limiting the flow of air into the fire (some refer to this as “smothering the fire”).  When using a reduced atmosphere to fire vessels, these turn black.

This Moche vessel at the Art Institute of Chicago seen here has a sculptural representation of a seated figure as the body of the vessel and a stirrup spout attached to the figure’s back. Two different slips create the cream and orange colors of the skin and fabric, and the surface has been thoroughly burnished. Additionally, a design has been incised on the figure’s face, which could represent a tattoo.