In the hands of a master, the coil and scrape technique can produce pottery of remarkable symmetry, closely resembling pottery fashioned on the potter's wheel. Decoration Materials Tools and Techniques of Ancient Southwest Pottery Painted decoration is the dominant decoration technique seen in pottery of the ancient Southwest, and utilizes slip, mineral and vegetal pigment or a combination of these materials. Slip is a mixture of clay and water sufficiently fluid to apply with a brush. Mineral and vegetal pigments were used to apply a dark, contrasting colored design to the pottery surface. A common mineral pigment used in pottery of the ancient Southwest is iron oxide, which will produce a red to black color, depending upon the firing atmosphere.
Manganese dioxide provides a black decoration, independent of firing atmosphere.
Vegetal pigments provide a dark decoration by producing a black carbon deposit on the pottery surface. Vegetal pigments are extremely sensitive to firing atmosphere, fading if the firing atmosphere is too rich in oxygen. Depending on the type of pigment being used, brushed decoration can present a degree of relief on the pottery surface if slip was used, and no relief if plant-based pigment was applied. Decorative pigments were applied to the pottery with brushes made from yucca. This plant has fibers that produce a fine point, and therefore are capable of producing fine line and detail.